Electricity and Electric Current

Electricity is used in homes, schools, hospitals, and industries for a wide range of purposes, including lighting, heating, powering appliances, and running machinery.

Electric current is the flow of electric charges through a conductor, like a metallic wire.

An electric circuit is a continuous and closed path through which electric current can flow.

<p>A switch acts as a connector or a breaker, allowing or preventing the flow of electric current in the circuit.</p> Signup and view all the answers

<p>Electric current is defined as the amount of electric charge flowing through a particular area in unit time.</p> Signup and view all the answers

<p>Electrons, which are negatively charged particles, constitute the flow of charge in circuits with metallic wires.</p> Signup and view all the answers

<p>The direction of electric current was traditionally taken as the flow of positive charges, even though electrons are the actual carriers of charge, because electrons were not known at the time when the phenomenon of electricity was first observed.</p> Signup and view all the answers

<p>When the circuit is broken, the flow of current stops because there is no continuous path for the charges to travel through.</p> Signup and view all the answers

<p>The cells or battery in a torch provide the flow of charges (electric current) through the bulb, causing it to glow.</p> Signup and view all the answers

<p>It means that charged particles, primarily electrons, are moving through the material of the conductor, creating an electric current.</p> Signup and view all the answers

<p>Electricity serves various purposes in homes, work, hospitals, and industries, providing controllable and convenient energy.</p> Signup and view all the answers

<p>Electric current is the flow of electric charge through a conductor.</p> Signup and view all the answers

<p>A torch or flashlight is a common example, where current flows through the bulb to make it glow.</p> Signup and view all the answers

<p>A closed path or circuit is necessary for continuous flow of current.</p> Signup and view all the answers

<p>A switch acts as a means to break or complete the conducting link in a circuit, allowing the flow of current to be controlled.</p> Signup and view all the answers

<p>Electric current is measured by the quantity of charge flowing through a specific area in a unit of time.</p> Signup and view all the answers

<p>Electrons, which are negatively charged particles, are responsible for current flow in metallic wires.</p> Signup and view all the answers

<p>The conventional direction of current was historically defined as the flow of positive charges, which was assumed as opposed to the actual flow of negative charges (electrons).</p> Signup and view all the answers

<p>If a circuit is broken, the flow of current stops, preventing further charge movement.</p> Signup and view all the answers

<p>A torch bulb lights up when current passes through it, causing the filament inside to heat up and emit light.</p> Signup and view all the answers

<p>The movement or flow of water molecules in a river corresponds to the flow of electric charges in a conductor.</p> Signup and view all the answers

<p>When the switch is off, the circuit is broken, halting the flow of current. The bulb will not light up because there's no current passing through it.</p> Signup and view all the answers

<p>A conducting link provides a continuous path for the electric current to flow through the circuit.</p> Signup and view all the answers

<p>Electric current is the rate of flow of electric charges through a given area in a specific unit of time.</p> Signup and view all the answers

<p>This convention stems from the historical understanding of electricity before the discovery of electrons, where the flow of positive charges was assumed to be the direction of current.</p> Signup and view all the answers

<p>Electricity offers flexibility in its application and control in diverse settings, making it valuable for various uses.</p> Signup and view all the answers

<p>The flow of current through the filament in the bulb causes it to heat up significantly, reaching a temperature where it emits light.</p> Signup and view all the answers

<p>A closed path ensures a continuous flow of current from the source, through the circuit components, and back to the source.</p> Signup and view all the answers

<p>Two essential conditions are a continuous closed path for current flow and a power source that provides the driving force (like a battery) for the charges.</p> Signup and view all the answers

<p>Both circuits and closed water systems utilize the movement of their respective substances (electric charges and water, respectively) in a continuous loop. Just as water must circulate through a closed pipe system, electric charges need a closed path within a circuit.</p> Signup and view all the answers

<p>Examples include electric heaters and electric ovens. Both utilize the heating effect of electric current to generate heat for various purposes.</p> Signup and view all the answers

<p>The current stops flowing, and the connected device, such as a bulb, does not glow.</p> Signup and view all the answers

<p>Historically, it was believed that positive charges flowed in circuits, leading to the convention of current direction being opposite to electron flow.</p> Signup and view all the answers

<p>Electric current is defined as the rate at which electric charge flows through a designated area over time.</p> Signup and view all the answers

<p>A continuous path, or closed circuit, is essential to allow electric current to flow uninterrupted and power connected devices.</p> Signup and view all the answers

<p>A battery provides the necessary electric charge, enabling the flow of current through the circuit.</p> Signup and view all the answers

<p>Just like water flows from high to low pressure, electric current flows from high voltage to low voltage through a conductor.</p> Signup and view all the answers

<p>A torch light illuminates when a closed circuit allows current to flow from the battery to the bulb.</p> Signup and view all the answers

<p>In metallic wires, free electrons move, constituting the flow of negative charge that creates the electric current.</p> Signup and view all the answers

<p>Resistance and voltage are the two key factors that regulate current in an electric circuit.</p> Signup and view all the answers

<p>When the circuit is open, the current ceases to flow, causing any powered devices to stop functioning.</p> Signup and view all the answers

<p>Ampere (A)</p> Signup and view all the answers

<p>I = Q/t</p> Signup and view all the answers

<p>6 × 10^18</p> Signup and view all the answers

<p>Ammeter</p> Signup and view all the answers

<p>Milliampere (mA)</p> Signup and view all the answers

<p>Electric current is the rate of flow of electric charge.</p> Signup and view all the answers

<p>From the positive terminal of the cell to the negative terminal.</p> Signup and view all the answers

<p>750 Coulombs (C)</p> Signup and view all the answers

<p>To ensure that the entire current flowing through the circuit also flows through the ammeter for accurate measurement.</p> Signup and view all the answers

<p>The amount of electric charge flowing through a conductor is directly proportional to the time it takes for the charge to flow.</p> Signup and view all the answers

<p>The electric charge $Q$ can be calculated using the formula $Q = I imes t$, where $I$ is the current in amperes and $t$ is the time in seconds.</p> Signup and view all the answers

<p>One ampere (A) is defined as the flow of one coulomb of charge per second, serving as the standard unit of electric current.</p> Signup and view all the answers

<p>One coulomb of electric charge is approximately equal to the charge of 6 × $10^{18}$ electrons, given that each electron has a charge of $1.6 × 10^{-19}$ C.</p> Signup and view all the answers

<p>An ammeter must be connected in series to measure the total current flowing through the circuit without altering the current's path.</p> Signup and view all the answers

<p>The current $I$ can be calculated using $I = Q/t = 2 ext{ C} / 4 ext{ s} = 0.5 ext{ A}$.</p> Signup and view all the answers

<p>A milliampere (mA) is one-thousandth of an ampere, defined as $1 ext{ mA} = 10^{-3} ext{ A}$.</p> Signup and view all the answers

<p>Electric current flows from the positive terminal of the battery to the negative terminal through the circuit components.</p> Signup and view all the answers

<p>To convert 3.5 A to milliamperes, multiply by 1000: $3.5 ext{ A} = 3500 ext{ mA}$.</p> Signup and view all the answers

<p>The time $t$ can be calculated as $t = Q/I = 3 ext{ C} / 1.5 ext{ A} = 2 ext{ s}$.</p> Signup and view all the answers

<p>The movement of electrons constitutes an electric current. Conventionally, the direction of current is considered opposite to the flow of electrons, meaning it flows from a point of higher potential to a point of lower potential. Thus, the movement of electrons from one point to another corresponds to a current flowing in the opposite direction.</p> Signup and view all the answers

<p>The ampere is defined as the flow of one coulomb of charge per second because it directly relates the quantity of charge flowing to the time taken. This definition helps to quantify and measure the rate of charge flow, which is essentially what electric current is.</p> Signup and view all the answers

<p>The total charge passing through the circuit would be 3000 Coulombs. We can calculate this using Equation 11.1 from the text: Charge (Q) = Current (I) x Time (t). Converting 10 minutes to seconds (600 seconds), we get Q = 5 A x 600 s = 3000 C.</p> Signup and view all the answers

<p>This statement highlights that one coulomb represents a substantial amount of charge, equivalent to the charge of a massive number of electrons. It signifies that even a small electric current involves the movement of a huge number of charged particles. This helps us understand the magnitude of charge flow involved in everyday electrical phenomena.</p> Signup and view all the answers

<p>The analogy that best represents 'flow of electric charges' in a conductor is the volume of water flowing through the pipe per unit time, which is equivalent to the flow rate. Just as the volume of water flowing per unit time represents the intensity of water flow, the amount of charge flowing through a conductor per unit time represents the intensity of electric current.</p> Signup and view all the answers

<p>If the filament breaks, the circuit is broken, and the flow of current ceases. This is because the filament acts as a conductor, and the broken filament will no longer allow the flow of charge through the circuit. As a result, the bulb will stop lighting up.</p> Signup and view all the answers

<p>An ammeter is connected in series to measure the current because it needs to measure the charge flow through that specific point in the circuit. Placing it in series ensures that all the charge passing through the circuit also passes through the ammeter, allowing for an accurate measurement of the current at that location.</p> Signup and view all the answers

<p>Two essential conditions are required for a continuous flow of electric current: (1) A closed circuit, meaning a continuous pathway for charges to flow without interruption, and (2) A source of potential difference, such as a battery, to provide the driving force for the charge flow. Without these conditions, the flow of charge will be interrupted, and no current will flow.</p> Signup and view all the answers

<p>When the switch is turned off, the circuit is broken, creating an open pathway for current to flow. This stops the flow of current, and the light bulb goes out. Turning the switch on closes the circuit, creating a continuous pathway for the current to flow, allowing the light bulb to turn on.</p> Signup and view all the answers

<p>A cell or battery in a circuit acts as the energy source. It provides a potential difference (voltage) across the circuit, which creates an electric field that drives the charges to flow. The higher the potential difference, the larger the electric field and the greater the flow of current in the circuit.</p> Signup and view all the answers

<p>A difference in electric pressure, known as potential difference.</p> Signup and view all the answers

<p>A battery.</p> Signup and view all the answers

<p>Electric potential difference between two points is the work done to move a unit charge from one point to the other.</p> Signup and view all the answers

<p>Volt (V).</p> Signup and view all the answers

<p>1 joule.</p> Signup and view all the answers

<p>Voltmeter.</p> Signup and view all the answers

<p>It is connected in parallel across the points where the potential difference is to be measured.</p> Signup and view all the answers

<p>Potential difference is essential for charges to flow and create an electric current in a conductor.</p> Signup and view all the answers

<p>The chemical energy is expended by the battery.</p> Signup and view all the answers

<p>Potential difference is the work done per unit charge.</p> Signup and view all the answers

<p>A potential difference, or difference in electric pressure, is necessary for charges to flow in a conductor.</p> Signup and view all the answers

<p>Electric potential difference (V) is defined as the work done (W) to move a unit charge (Q) from one point to another in an electric circuit: V = W/Q.</p> Signup and view all the answers

<p>The SI unit for electric potential difference is the volt (V), named after Alessandro Volta. One volt is the potential difference required to move one coulomb of charge when one joule of work is done.</p> Signup and view all the answers

<p>$W = QV = (3 C)(6 V) = 18 J$</p> Signup and view all the answers

<p>A voltmeter measures the potential difference between two points in a circuit. It is always connected in parallel across the points where the potential difference is to be measured.</p> Signup and view all the answers

<p>If the circuit is broken, the potential difference across the bulb would disappear, and the electric current would stop flowing. As a result, the light bulb would cease to glow.</p> Signup and view all the answers

<p>A battery provides the potential difference, or electric pressure, required for the electric charges to move in a circuit. Chemical reactions within the battery create a difference in potential between its terminals, pushing charges through the circuit.</p> Signup and view all the answers

<p>In a horizontal pipe, water flows only if there's a pressure difference between the ends, caused by a difference in height. Similarly, electric charges in a conductor flow only if there's a potential difference across the conductor, created by a battery or other source. The pressure difference in the pipe and the potential difference in the conductor both determine the direction and magnitude of the flow.</p> Signup and view all the answers

<p>Electric potential is the amount of electric potential energy per unit of charge at a particular point in an electric field. Potential difference is the difference in electric potential between two points in an electric field. The flow of electric charges in a conductor is driven by the potential difference, which is the difference in electric potential energy between the two points.</p> Signup and view all the answers

<p>The battery's chemical energy creates a potential difference across its terminals. This potential difference drives electric current through the circuit, including the bulb's filament. The filament has high resistance, causing the flowing charges to lose energy and release heat. This heat causes the filament to glow, emitting light.</p> Signup and view all the answers

<p>The potential difference creates an electric pressure that sets charges in motion within the conductor, enabling the flow of electric current.</p> Signup and view all the answers

<p>Electric potential difference (V) is defined as the work done (W) to move a unit charge (Q) from one point to another, expressed as V = W/Q.</p> Signup and view all the answers

<p>A voltmeter is used to measure electric potential difference, and it is connected in parallel across the two points of interest in the circuit.</p> Signup and view all the answers

<p>A battery generates potential difference through chemical reactions, which produces an electric field that moves charges and creates a current in the circuit.</p> Signup and view all the answers

<p>One volt is defined as the potential difference needed to do one joule of work on one coulomb of charge, indicating the strength of the electric field.</p> Signup and view all the answers

<p>Just as water flows due to a pressure difference in a tube, electric charges flow in a metallic conductor due to a potential difference.</p> Signup and view all the answers

<p>When a cell is not connected to a circuit, no current flows, but the potential difference exists at the terminals of the cell due to stored chemical energy.</p> Signup and view all the answers

<p>The work done is 24 joules, calculated using the formula W = V * Q, where W = 12 V * 2 C.</p> Signup and view all the answers

<p>The potential difference represents the energy per unit charge transferred in the circuit, adhering to the law of conservation of energy as energy is converted in the process.</p> Signup and view all the answers

<p>A potential difference creates an electric field that exerts a force on the electrons, causing them to drift and create an electric current.</p> Signup and view all the answers

<p>P = VI (Power = Voltage × Current)</p> Signup and view all the answers

<p>Watt (W)</p> Signup and view all the answers

<p>To control the flow of electric current in the circuit.</p> Signup and view all the answers

<p>A cell or battery, a plug key, an electrical component, and connecting wires.</p> Signup and view all the answers

<p>It connects two or more wires to create a continuous path for the flow of electric current.</p> Signup and view all the answers

<p>They are not electrically connected.</p> Signup and view all the answers

<p>The potential difference between two points is equal to the work done (or energy given) in moving a unit positive charge from one point to the other.</p> Signup and view all the answers

<p>A battery</p> Signup and view all the answers

<p>It means that 1 Joule of work is done in moving 1 Coulomb of charge from one point to the other.</p> Signup and view all the answers

<p>A battery provides the electromotive force (EMF) that drives electric current through a circuit. It acts as a source of energy by converting chemical energy into electrical energy. One example of a commonly used battery is a lead-acid battery, found in cars.</p> Signup and view all the answers

<p>A switch acts as a gatekeeper, controlling the flow of current in the circuit. When open, it breaks the circuit, preventing current flow. When closed, it completes the circuit, allowing current to pass through.</p> Signup and view all the answers

<p>Increasing the voltage of the battery will make the bulb brighter. This is because higher voltage drives more current through the bulb, resulting in greater power dissipation and light output.</p> Signup and view all the answers

<p>The potential difference across a component represents the amount of energy transferred to each unit charge (one Coulomb) as it moves through the component. In other words, the voltage is the energy per unit charge.</p> Signup and view all the answers

<p>Electrical resistance is a property that opposes the flow of electric current through a conductor. Factors that influence resistance include the material's conductivity, the conductor's length (longer conductors offer more resistance), and its cross-sectional area (thicker conductors have lower resistance).</p> Signup and view all the answers

<p>Ohm's law defines the relationship between current (I), voltage (V), and resistance (R) in an electric circuit. It states that the current flowing through a conductor is directly proportional to the voltage applied across its ends and inversely proportional to its resistance. The equation is: I = V/R.</p> Signup and view all the answers

<p>Power in an electric circuit refers to the rate at which electrical energy is consumed or transferred. It is measured in watts (W). The power (P) is calculated as the product of voltage (V) and current (I): P = V x I</p> Signup and view all the answers

<p>In a series circuit, components are connected end-to-end, forming a single path for current flow. If one component fails, the entire circuit breaks. Example: Christmas lights. In a parallel circuit, components are connected across each other, providing multiple paths for current flow. If one component fails, the others continue to function. Example: household wiring.</p> Signup and view all the answers

<p>Electricity can be dangerous if not handled properly. It can cause electrical shocks, fires, and even death. Therefore, it is crucial to follow safety precautions such as using insulated tools, avoiding contact with wet surfaces, and being aware of potential hazards.</p> Signup and view all the answers

<p>Direct current (DC) flows in one direction, while alternating current (AC) periodically reverses its direction. DC is used in devices like batteries and smartphones, while AC is used in household power outlets and power grids.</p> Signup and view all the answers

<p>The bulb will become brighter. Increasing the potential difference across the bulb increases the electrical energy supplied to the bulb, resulting in a higher rate of energy conversion into light. This leads to a brighter illumination.</p> Signup and view all the answers

<p>When the switch is opened, the circuit is broken, interrupting the flow of current. The light bulb will immediately stop glowing as the flow of electrons ceases, and the bulb no longer receives electrical energy to produce light.</p> Signup and view all the answers

<p>The potential difference across a conductor provides the driving force for electric current. It creates an electric field that pushes charges through the conductor, resulting in the flow of electric current.</p> Signup and view all the answers

<p>Circuit diagrams use standardized symbols to simplify the representation of components, making it easier to understand the flow of current within the system and to identify the specific components involved. Visualizing the circuit's structure becomes more efficient and less cluttered.</p> Signup and view all the answers

<p>The potential difference across a conductor reflects the work done per unit charge to move the charge from one point to another. Therefore, the energy given to each Coulomb of charge passing through a conductor is directly proportional to the potential difference across it. In essence, a higher potential difference implies a larger amount of energy imparted to each Coulomb of charge.</p> Signup and view all the answers

<p>Just as water flows through a pipe due to a pressure difference, electric current flows through a wire due to a potential difference. The pressure difference pushes water, while the potential difference drives the flow of electrons. The analogy emphasizes the concept of a driving force and the movement of something (water or electrons) through a conduit.</p> Signup and view all the answers

<p>When a circuit is broken, the flow of current stops. This is because a complete path for the electrons to travel is no longer present. An unbroken circuit provides a continuous path for electrons to flow from the battery to the components and back, while a broken circuit interrupts this path, preventing current flow.</p> Signup and view all the answers

<p>The potential difference across a battery represents the work done per unit charge in moving a charge from the negative terminal to the positive terminal. Each Coulomb of charge passing through the battery gains an amount of energy equal to the potential difference across the battery. A higher potential difference implies a greater energy transfer per Coulomb.</p> Signup and view all the answers

<p>A closed circuit provides a complete path for electrons to flow from the battery to the components and back. This continuous path allows for the uninterrupted flow of current. An open circuit, on the other hand, has a break in the path, preventing electrons from completing the circuit, resulting in no current flow.</p> Signup and view all the answers

<p>Nichrome</p> Signup and view all the answers

<p>To measure the electric current flowing through the nichrome wire.</p> Signup and view all the answers

<p>By the variable 'V' and measured in volts.</p> Signup and view all the answers

<p>By the variable 'I' and measured in amperes.</p> Signup and view all the answers

<p>The relationship between potential difference (V) and current (I) across a conductor.</p> Signup and view all the answers

<p>$V/I$</p> Signup and view all the answers

<p>Potential difference (V).</p> Signup and view all the answers

<p>To provide the source of electrical energy.</p> Signup and view all the answers

<p>The voltmeter measures the potential difference across the nichrome wire, allowing for the calculation of voltage in relation to current.</p> Signup and view all the answers

<p>According to Ohm's law, if the resistance remains constant, an increase in voltage leads to a proportional increase in current.</p> Signup and view all the answers

<p>It implies that the nichrome wire obeys Ohm's law and has a constant resistance.</p> Signup and view all the answers

<p>Adding an additional cell increases the voltage, which in turn typically increases the current through the circuit.</p> Signup and view all the answers

<p>Plotting the graph helps visualize the linear relationship between voltage and current, confirming Ohm's law if the graph is a straight line.</p> Signup and view all the answers

<p>Tabulating the readings allows for systematic analysis and easier comparison of results to calculate the ratio of $V$ to $I$.</p> Signup and view all the answers

<p>Nichrome is an alloy composed of nickel, chromium, manganese, and iron.</p> Signup and view all the answers

<p>Using four cells demonstrates the effect of increased voltage on current, providing multiple data points for analysis.</p> Signup and view all the answers

<p>The ammeter measures the current flowing through the circuit, essential for determining the relationship with voltage.</p> Signup and view all the answers

<p>It demonstrates how changing voltage affects current, illustrating Ohm's law in practice.</p> Signup and view all the answers

<p>The resistance of nichrome wire limits the amount of current that can flow, as described by Ohm's Law, which states $V = IR$.</p> Signup and view all the answers

<p>The ratio $V/I$ remains constant for a given resistor, as per Ohm's Law, indicating that the conductor behaves linearly as long as it stays within its limits.</p> Signup and view all the answers

<p>The graph is expected to be a straight line passing through the origin, indicating a linear relationship between current and voltage.</p> Signup and view all the answers

<p>The ammeter must be connected in series to accurately measure the current flowing through the entire circuit without altering it.</p> Signup and view all the answers

<p>By calculating the ratio $V/I$ from the voltmeter and ammeter readings, one can determine the resistance and verify Ohm's Law.</p> Signup and view all the answers

<p>The temperature of the nichrome wire can affect its resistance; as temperature increases, resistance typically increases, impacting current measurements.</p> Signup and view all the answers

<p>Using multiple cells increases the total potential difference across the nichrome wire, which in turn can increase the current flowing through the circuit.</p> Signup and view all the answers

<p>The circuit must remain closed and undamaged, ensuring a complete path for current flow to obtain reliable readings.</p> Signup and view all the answers

<p>Nichrome is chosen for its stable resistance and ability to withstand high temperatures without significant changes in resistance.</p> Signup and view all the answers

<p>A consistent $V/I$ ratio indicates that the nichrome wire behaves as an Ohmic material, following Ohm's Law in all configurations tested.</p> Signup and view all the answers

<p>The current gets halved.</p> Signup and view all the answers

<p>A rheostat is used to regulate current without changing the voltage source.</p> Signup and view all the answers

<p>A rheostat.</p> Signup and view all the answers

<p>I = V/R.</p> Signup and view all the answers

<p>6 V.</p> Signup and view all the answers

<p>An ammeter.</p> Signup and view all the answers

<p>The current decreases.</p> Signup and view all the answers

<p>0 – 5 A.</p> Signup and view all the answers

<p>It allows for the regulation of current in electric circuits.</p> Signup and view all the answers

<p>The ammeter.</p> Signup and view all the answers

<p>Ohm's law states that the potential difference (V) across a metallic wire is directly proportional to the current (I) flowing through it, represented as V = IR.</p> Signup and view all the answers

<p>The constant ratio in Ohm's law is expressed as V/I = R, where R is the resistance of the wire.</p> Signup and view all the answers

<p>The SI unit for resistance is the ohm, represented by the Greek letter Ω.</p> Signup and view all the answers

<p>The V-I graph for a metallic wire is a straight line that passes through the origin, indicating a linear relationship between voltage and current.</p> Signup and view all the answers

<p>Using Ohm's law, the resistance R can be calculated as R = V/I = 10V/2A = 5 Ω.</p> Signup and view all the answers

<p>Typically, the resistance of a metallic wire increases with temperature due to increased collisions between charge carriers.</p> Signup and view all the answers

<p>The equation R = V/I signifies that resistance is calculated as the ratio of potential difference (V) to current (I).</p> Signup and view all the answers

<p>A resistance of 1 Ω means that a potential difference of 1 V results in a current of 1 A through the wire.</p> Signup and view all the answers

<p>A straight line in the V-I graph implies Ohm's law holds true, indicating constant resistance across varying current levels.</p> Signup and view all the answers

<p>Ohm's law was developed by German physicist Georg Simon Ohm in 1827.</p> Signup and view all the answers

<p>Ohm's law states that the voltage (V) across a conductor is directly proportional to the current (I) flowing through it, provided the temperature remains constant. Mathematically, this is represented as V = IR, where R is the resistance of the conductor.</p> Signup and view all the answers

<p>The SI unit of resistance is the ohm, represented by the Greek letter Ω (omega).</p> Signup and view all the answers

<p>Resistance is an intrinsic property of a conductor that determines how much it hinders the flow of electric current. It depends on the material, length, cross-sectional area, and temperature of the conductor.</p> Signup and view all the answers

<p>Ohm's law states that voltage is directly proportional to current and resistance: V = IR. This means that if you increase the voltage, the current will also increase, assuming the resistance remains constant.</p> Signup and view all the answers

<p>The resistance of the conductor is 1 ohm. This is because resistance is defined as the ratio of voltage to current: R = V/I. So, if V = 1 volt and I = 1 ampere, then R = 1 ohm.</p> Signup and view all the answers

<p>It implies that the resistance of the metallic wire is constant regardless of the current flowing through it. This is characteristic of materials obeying Ohm's law.</p> Signup and view all the answers

<p>The resistance of a metallic wire is directly proportional to its length and inversely proportional to its cross-sectional area. This means that a longer wire has higher resistance, while a wire with a larger cross-sectional area has lower resistance.</p> Signup and view all the answers

<p>Resistance is like friction in a pipe. It slows down the flow of water (electrons) through the pipe (conductor). The narrower the pipe, the more friction (resistance) there is, making it harder for water to flow.</p> Signup and view all the answers

<p>Resistance in an electrical wire can be compared to traffic congestion on a highway. A narrow highway (high resistance) restricts the flow of cars (electrons), while a wide, clear highway (low resistance) allows cars to flow freely.</p> Signup and view all the answers

<p>The resistance of a metallic wire changes with temperature. If the temperature is not kept constant, the relationship between voltage and current will not be a linear one, and Ohm's law will not be applicable.</p> Signup and view all the answers

<p>According to Ohm's law, increasing the resistance will decrease the current, as they are inversely proportional.</p> Signup and view all the answers

<p>A rheostat is a variable resistor used to adjust the current in a circuit without altering the voltage source.</p> Signup and view all the answers

<p>The necessary components include a nichrome wire, a torch bulb, a 10 W bulb, an ammeter, a plug key, and connecting wires.</p> Signup and view all the answers

<p>Doubling the resistance in a circuit halves the current flow, according to Ohm's law.</p> Signup and view all the answers

<p>Variable resistance is necessary to control and adjust the current flow according to specific requirements of different applications.</p> Signup and view all the answers

<p>The ammeter measures the electric current flowing through the circuit.</p> Signup and view all the answers

<p>The circuit setup with various components allows students to observe how changes in resistance affect current flow.</p> Signup and view all the answers

<p>If the plug key is opened, the circuit becomes incomplete, and the current stops flowing.</p> Signup and view all the answers

<p>Nichrome wire is used in the activity due to its high resistance, which allows for measurable current changes.</p> Signup and view all the answers

<p>Resistance is crucial for regulating current, ensuring devices operate within safe and efficient parameters.</p> Signup and view all the answers

<p>Ohm's Law states that the potential difference (V) across a metallic wire is directly proportional to the current (I) flowing through it, provided the temperature of the wire remains constant. This relationship can be expressed as V = IR, where R is the resistance of the wire.</p> Signup and view all the answers

<p>Resistance is the property of a conductor that opposes the flow of electric charges through it. The higher the resistance, the more difficult it is for charges to move through the conductor, leading to a smaller current for a given potential difference.</p> Signup and view all the answers

<p>The resistance (R) of a conductor is defined as the ratio of the potential difference (V) across its ends to the current (I) flowing through it: R = V/I. The SI unit of resistance is the ohm (Ω).</p> Signup and view all the answers

<p>The V–I graph for a metallic wire is a straight line passing through the origin because the potential difference (V) is directly proportional to the current (I) according to Ohm's Law. This linearity indicates a constant ratio between voltage and current, which is the resistance of the wire.</p> Signup and view all the answers

<p>The slope of the V–I graph represents the resistance (R) of the metallic wire. The steeper the slope, the greater the resistance, meaning a larger potential difference is needed to drive a given current through the wire.</p> Signup and view all the answers

<p>The resistance of a metallic wire is directly proportional to its length (L) and inversely proportional to its cross-sectional area (A). This means that a longer wire has higher resistance, while a wire with a larger cross-sectional area has lower resistance. This can be explained by considering the path that charge carriers must travel through the wire and the number of available pathways for charge flow.</p> Signup and view all the answers

<p>The resistance of most materials increases with temperature. This is due to the increased thermal motion of atoms within the material, which hinders the flow of charge carriers. For example, the filament in an incandescent light bulb heats up as current flows through it, causing its resistance to increase and leading to the emission of light.</p> Signup and view all the answers

<p>The resistance of a conductor is influenced by its material, length, cross-sectional area, and temperature. Increasing the length, lowering the cross-sectional area, using a material with higher resistivity, or increasing the temperature all contribute to higher resistance. These factors ultimately affect the current flow in an electric circuit.</p> Signup and view all the answers

<p>Nichrome wire is used as the heating element in an electric heater because it has a high resistance and a high melting point. When current flows through the nichrome wire, its high resistance causes the wire to heat up significantly. This thermal energy is then transferred to the surrounding air, providing heat.</p> Signup and view all the answers

<p>According to Ohm's Law (V = IR), if the voltage (V) is constant and the resistance (R) is increased, the current (I) in the circuit will decrease. This is because the current is inversely proportional to the resistance. A higher resistance impedes the flow of charge, resulting in a lower current.</p> Signup and view all the answers

<p>Equation (11.7) states that current (I) is inversely proportional to resistance (R), meaning that as resistance increases, current decreases proportionally, and vice versa. For instance, doubling the resistance would halve the current.</p> Signup and view all the answers

<p>A variable resistance component allows for regulating current without altering the voltage source. This is crucial for controlling the amount of current flowing through a circuit. A common component used for this purpose is called a rheostat.</p> Signup and view all the answers

<p>The setup includes a nichrome wire, a torch bulb, a 10 W bulb, an ammeter, a plug key, and connecting wires. Four 1.5 V dry cells are connected in series, followed by the ammeter and a gap XY. The gap allows for inserting different components (like the nichrome wire, torch bulb, or 10 W bulb) for studying their resistance and current flow.</p> Signup and view all the answers

<p>The current measured by the ammeter will be different for each component due to their varying resistances. The component with the highest resistance will result in the lowest current, while the component with the lowest resistance will have the highest current. This is because current is inversely proportional to resistance.</p> Signup and view all the answers

<p>To determine the resistance of each component, we need to measure the voltage across it and the current flowing through it. We can connect the chosen component across the gap XY. Measure the voltage across it using a voltmeter connected in parallel. Then, with the ammeter connected in series, measure the current flowing through it. Resistance can then be calculated using Ohm's law: R = V/I.</p> Signup and view all the answers

<p>Increasing the number of dry cells in series will result in an increased voltage across the circuit. Since current is directly proportional to voltage (I = V/R), the current flowing through the circuit will also increase.</p> Signup and view all the answers

<p>The bulb connected to the 12 V battery will be brighter. This is because the bulb's brightness is directly proportional to the power it consumes, and power is given by P = V*I. With a higher voltage, the bulb will have a higher current (due to I = V/R), resulting in greater power dissipation and hence higher brightness.</p> Signup and view all the answers

<p>A fuse is a safety device with low resistance. When excessive current flows through a circuit, the fuse's low resistance causes it to heat up rapidly. This heat melts the fuse wire, breaking the circuit and preventing further current flow, thus protecting appliances from damage caused by overheating.</p> Signup and view all the answers

<p>For a toy car circuit, key factors include selecting a suitable power source (battery voltage), using appropriate wire gauge and connectors to handle the expected current, considering the resistance of the motor and lights, and incorporating a fuse for safety. All these factors need to be balanced to avoid excessive heating, overloading, and potential hazards.</p> Signup and view all the answers

<p>When the switch is closed, the circuit is complete, allowing current to flow from the battery, through the wires, the light bulb, and back to the battery. The light bulb illuminates. When the switch is open, the circuit is broken, disrupting the current flow. The current stops, and the light bulb goes out.</p> Signup and view all the answers

<p>The ammeter readings will differ for each component.</p> Signup and view all the answers

<p>The components have different resistances, affecting how easily electric current can flow.</p> Signup and view all the answers

<p>Conductor.</p> Signup and view all the answers

<p>Resistor.</p> Signup and view all the answers

<p>The motion of electrons is retarded by the attraction of the atoms in the conductor.</p> Signup and view all the answers

<p>By measuring the current flow using an ammeter for each material.</p> Signup and view all the answers

<p>Insulators do not allow electric current to flow freely due to their very high resistance.</p> Signup and view all the answers

<p>The ammeter measures the amount of electric current flowing through the circuit.</p> Signup and view all the answers

<p>Always take out the key from the plug to safely disconnect the circuit.</p> Signup and view all the answers

<p>Different components influence current flow based on their respective resistances.</p> Signup and view all the answers

<p>An increase in resistance indicates that the component offers more opposition to the flow of electric current, making it a poorer conductor.</p> Signup and view all the answers

<p>The ammeter readings differ because each component has a unique resistance that affects the amount of current flowing through the circuit.</p> Signup and view all the answers

<p>A component with low resistance allows electrons to move more freely, thus enabling a higher flow of electric current.</p> Signup and view all the answers

<p>Disconnecting the key prevents any risk of electrical shock and protects the circuit components from damage.</p> Signup and view all the answers

<p>The nichrome wire serves as a conductor with a measurable resistance that allows for current flow to be observed.</p> Signup and view all the answers

<p>The observation would likely show a very low ammeter reading, indicating minimal current flow.</p> Signup and view all the answers

<p>Resistance slows down the motion of electrons, which reduces the overall flow of electric current in the circuit.</p> Signup and view all the answers

<p>If all components have similar resistance, they would likely allow for a comparable amount of current to flow through the circuit.</p> Signup and view all the answers

<p>A conductor allows electric current to flow easily, while an insulator resists the flow of current.</p> Signup and view all the answers

<p>Comparing ammeter readings helps to demonstrate the varying levels of resistance and conductivity between different materials.</p> Signup and view all the answers

<p>The components tested likely have low resistance.</p> Signup and view all the answers

<p>Resistance.</p> Signup and view all the answers

<p>Higher resistance restricts the movement of electrons, while lower resistance allows for easier electron flow.</p> Signup and view all the answers

<p>A component with high resistance would be classified as a poor conductor or an insulator.</p> Signup and view all the answers

<p>Plugging in the key before connecting a component in the gap could potentially create a short circuit, which could damage the circuit or be dangerous.</p> Signup and view all the answers

<p>Leaving the key plugged in after taking a measurement could waste battery power and potentially overheat the circuit.</p> Signup and view all the answers

<p>The ammeter measures the amount of electric current flowing through the circuit. It gives information about the rate of charge flow.</p> Signup and view all the answers

<p>The ammeter reading would likely decrease because the resistance of the wire would increase.</p> Signup and view all the answers

<p>The width of the pipe or the presence of obstacles within the pipe would correspond to the resistance of a conductor.</p> Signup and view all the answers

<p>The size of the component is mentioned because resistance is also dependent on the dimensions of the conductor, not just the material. For instance, a thicker wire of the same material would provide less resistance than a thinner wire.</p> Signup and view all the answers

<p>The resistance of a wire is directly proportional to its length. This means that as the length of the wire increases, the resistance also increases.</p> Signup and view all the answers

<p>The resistance of a wire is inversely proportional to its cross-sectional area. This means that as the cross-sectional area of the wire increases, the resistance decreases.</p> Signup and view all the answers

<p>The resistance of a conductor depends on its length, its cross-sectional area, and the material it is made of.</p> Signup and view all the answers

<p>The resistance of the wire will also double.</p> Signup and view all the answers

<p>The resistance of the wire will double.</p> Signup and view all the answers

<p>A larger cross-sectional area implies more space for free electrons to move. This increased space reduces the likelihood of collisions between electrons and the wire's atoms, leading to lower resistance.</p> Signup and view all the answers

<p>Different materials have different numbers of free electrons and different atomic structures, which influence how easily electrons can move through them.</p> Signup and view all the answers

<p>The resistance (R) of a uniform metallic conductor is directly proportional to its length (l) and inversely proportional to its cross-sectional area (A). This can be expressed as: $R \propto \frac{l}{A}$</p> Signup and view all the answers

<p>A longer wire provides a longer path for the electrons to travel, increasing the chances of collisions with the atoms of the wire. These collisions impede the flow of electrons, resulting in higher resistance.</p> Signup and view all the answers

<p>Resistance is a measure of the opposition to the flow of current through a conductor. A higher resistance signifies greater difficulty for current to flow, while a lower resistance indicates easier current flow.</p> Signup and view all the answers

<p>The current is reduced to one-half when the length of the nichrome wire is doubled.</p> Signup and view all the answers

<p>Increasing the cross-sectional area of a wire results in an increased current through the circuit.</p> Signup and view all the answers

<p>The current reading for the copper wire will be higher than that for the nichrome wire.</p> Signup and view all the answers

<p>Resistance is directly proportional to length (R ∝ l) and inversely proportional to area (R ∝ 1/A).</p> Signup and view all the answers

<p>The material influences the resistance due to its intrinsic properties, such as conductivity.</p> Signup and view all the answers

<p>The current will vary based on the material, with conductive materials allowing more current to flow.</p> Signup and view all the answers

<p>The ammeter reading increases when a thicker wire of the same length is used.</p> Signup and view all the answers

<p>Resistance increases with length and decreases with larger cross-sectional area.</p> Signup and view all the answers

<p>No, the current cannot remain the same because different materials have different resistances.</p> Signup and view all the answers

<p>The resistance will double. Resistance is directly proportional to the length of the wire. Doubling the length means doubling the resistance.</p> Signup and view all the answers

<p>The nichrome wire will have a higher resistance. Different materials have different resistivities, which is an intrinsic property affecting their resistance. Nichrome has a higher resistivity than copper.</p> Signup and view all the answers

<p>Resistance is inversely proportional to the area of cross-section. A larger cross-sectional area means lower resistance because there is more space for electrons to flow, leading to reduced collisions and less opposition to current.</p> Signup and view all the answers

<p>R = (ρl)/A. Resistivity is directly proportional to resistance, and resistance is directly proportional to length and inversely proportional to cross-sectional area.</p> Signup and view all the answers

<p>Replacing the initial wire with a longer one of the same material and thickness results in a decrease in current. This indicates that resistance increases with length, causing a drop in current.</p> Signup and view all the answers

<p>The current increased when using a thicker wire of the same length and material. This indicates that resistance decreases with an increase in cross-sectional area, allowing more current to flow.</p> Signup and view all the answers

<p>The experiment shows that different materials have different resistances even when the length and cross-sectional area are the same. This suggests that the material itself has an intrinsic property affecting resistance.</p> Signup and view all the answers

<p>The resistance would increase to 40 ohms. Doubling the length increases the resistance by a factor of 2, and halving the area increases the resistance by a factor of 2. The combined effect is a 4-fold increase in resistance.</p> Signup and view all the answers

<p>Ohm's law establishes a direct proportionality between voltage and current, with resistance being the constant of proportionality. The experiment shows that resistance increases with length and decreases with area, directly impacting current through the relationship defined by Ohm's law.</p> Signup and view all the answers

<p>Factors determining resistance are length, cross-sectional area, and material. Increased length means more resistance and less current. Increased area means less resistance and more current. Different materials have different inherent resistivities, affecting their resistance, thus affecting the flow of current.</p> Signup and view all the answers

<p>10–8 Ω m to 10–6 Ω m</p> Signup and view all the answers

<p>1012 to 1017 Ω m</p> Signup and view all the answers

<p>Higher</p> Signup and view all the answers

<p>They do not oxidize readily at high temperatures.</p> Signup and view all the answers

<p>Tungsten</p> Signup and view all the answers

<p>Copper and aluminium</p> Signup and view all the answers

<p>Nichrome</p> Signup and view all the answers

<p>1.60 × 10–8 Ω m</p> Signup and view all the answers

<p>Resistivity generally increases with increasing temperature.</p> Signup and view all the answers

<p>Diamond</p> Signup and view all the answers

<p>Alloys do not oxidise readily at high temperatures, which makes them ideal for electrical heating devices.</p> Signup and view all the answers

<p>Conductors have lower resistivity because they allow easier flow of electric charge, while insulators resist the flow.</p> Signup and view all the answers

<p>Copper, with a resistivity of $1.62 \times 10^{-8} , \text{Ω m}$.</p> Signup and view all the answers

<p>Both resistance and resistivity of a material typically vary with temperature, generally increasing with temperature for conductors.</p> Signup and view all the answers

<p>Good conductors have a resistivity range from $10^{-8} \text{Ω m}$ to $10^{-6} \text{Ω m}$.</p> Signup and view all the answers

<p>Tungsten has a high melting point and low resistivity, making it ideal for withstand the heat in bulb filaments.</p> Signup and view all the answers

<p>The resistivity of an alloy is generally higher than that of its constituent metals.</p> Signup and view all the answers

<p>Hard rubber has a resistivity range of $10^{13}$ to $10^{16} \text{Ω m}$, making it an excellent insulator.</p> Signup and view all the answers

<p>Constantan has a resistivity of $49 \times 10^{-6} \text{Ω m}$ and is an alloy of copper and nickel.</p> Signup and view all the answers

<p>Insulators like glass have resistivity values in the range of $10^{10}$ to $10^{14} \text{Ω m}$.</p> Signup and view all the answers

<p>The typical resistivity range for good conductors is from $10^{-8} , ext{Ω m}$ to $10^{-6} , ext{Ω m}$.</p> Signup and view all the answers

<p>Alloys are preferred because they do not oxidize readily at high temperatures.</p> Signup and view all the answers

<p>Tungsten is used for filaments, with a resistivity of $5.20 \times 10^{-8} , \text{Ω m}$. Copper and aluminium are used for transmission lines, with resistivities of $1.62 \times 10^{-8} , \text{Ω m}$ and $2.63 \times 10^{-8} , \text{Ω m}$ respectively.</p> Signup and view all the answers

<p>The resistivity of glass ranges from $10^{10}$ to $10^{14} , ext{Ω m}$, while hard rubber ranges from $10^{13}$ to $10^{16} , ext{Ω m}$.</p> Signup and view all the answers

<p>The resistivity of an alloy is generally higher than that of its constituent metals.</p> Signup and view all the answers

<p>Alloys do not oxidize or burn readily at high temperatures.</p> Signup and view all the answers

<p>Constantan has a resistivity of $49 \times 10^{-6} , \text{Ω m}$ and is an alloy of copper and nickel.</p> Signup and view all the answers

<p>Diamond has a resistivity range of $10^{12}$ to $10^{13} , ext{Ω m}$, making it a good insulator.</p> Signup and view all the answers

<p>Mercury has a resistivity of $94.0 \times 10^{-8} , \text{Ω m}$.</p> Signup and view all the answers

<p>It is unnecessary to memorize these values as they can be referred to for solving numerical problems.</p> Signup and view all the answers

<p>8 A</p> Signup and view all the answers

<p>1.84 × 10–6 Ω m</p> Signup and view all the answers

<p>1 Ω</p> Signup and view all the answers

<p>R = V/I</p> Signup and view all the answers

<p>26 Ω</p> Signup and view all the answers

<p>Resistance decreases as diameter increases.</p> Signup and view all the answers

<p>Ohm's law</p> Signup and view all the answers

<p>Resistance is reduced to 2 Ω.</p> Signup and view all the answers

<p>Higher resistivity results in higher resistance.</p> Signup and view all the answers

<p>60 V</p> Signup and view all the answers

<p>The formula is $I = \frac{V}{R}$, where $I$ is the current, $V$ is the potential difference, and $R$ is the resistance.</p> Signup and view all the answers

<p>The current drawn becomes 8 A.</p> Signup and view all the answers

<p>The resistivity is $\rho = 1.84 \times 10^{-6} \Omega m$.</p> Signup and view all the answers

<p>The new resistance is 1 Ω.</p> Signup and view all the answers

<p>The formula used is $R = \frac{\rho l}{A}$.</p> Signup and view all the answers

<p>The resistance would be 8 Ω.</p> Signup and view all the answers

<p>Current refers to the flow of electric charge in a circuit.</p> Signup and view all the answers

<p>Potential difference provides the driving force that pushes electric charges through the circuit.</p> Signup and view all the answers

<p>Ohm's Law states that current is directly proportional to voltage and inversely proportional to resistance.</p> Signup and view all the answers

<p>Ohm's Law, which states that the current (I) through a conductor is directly proportional to the potential difference (V) across its ends, explains this behavior. As the voltage increases, the current also increases proportionally, assuming the resistance remains constant.</p> Signup and view all the answers

<p>The formula ρ = (RA/l) is used because it directly connects resistance (R), area (A), and length (l) to resistivity (ρ). Resistivity is an intrinsic property of the material, representing its resistance to electric current flow. The formula allows for calculation of this property based on measurable quantities of the wire.</p> Signup and view all the answers

<p>Resistance is directly proportional to length and inversely proportional to area. Halving the length reduces the resistance, while doubling the area also reduces the resistance. This is evident as the resistance of the new wire (R2) is 1/4th of the original wire, due to both changes in length and area.</p> Signup and view all the answers

<p>A wire with high resistivity would significantly impede the flow of current, meaning a large potential difference would be required to achieve a moderate current. Materials like rubber or glass have very high resistivities, making them suitable for insulation.</p> Signup and view all the answers

<p>Resistivity (ρ) is a constant for a specific material, while resistance (R) is dependent on the wire's dimensions. The formula shows that resistance is directly proportional to resistivity, meaning that a material with higher resistivity will have a higher resistance for a given length and area.</p> Signup and view all the answers

<p>Resistance is the opposition to the flow of electric current. It acts like a barrier, reducing the amount of current that can flow through a circuit for a given voltage. A resistor is a component specifically designed to provide a known amount of resistance, and is often used to control the current or voltage in a circuit.</p> Signup and view all the answers

<p>The resistance of the wire would increase. Resistance is directly proportional to length, so increasing the length would increase the resistance. This is because there is a longer path for the electric current to travel, increasing the opportunity for collisions with atoms and hence reducing current flow.</p> Signup and view all the answers

<p>The bulb is not lit because the circuit is incomplete. The wire needs to be connected to the negative terminal of the battery to complete the path for current to flow from the battery, through the bulb, and back to the battery. By connecting to the negative terminal, a closed circuit is formed allowing current flow and the bulb will light up.</p> Signup and view all the answers

<p>The thinner wire will have a higher resistance. Since the thicker wire has a larger cross-sectional area, it offers less resistance to current flow. The electrons have more space to move through and are less likely to collide with atoms, leading to less opposition to current flow.</p> Signup and view all the answers

<p>While doubling the voltage does double the current in this specific case, this linear relationship holds true only if the resistance remains constant. In reality, many conductors have non-linear resistance properties, meaning their resistance can change depending on factors like temperature or current level. Therefore, this relationship isn't always universally applicable.</p> Signup and view all the answers

<p>The resistance of a conductor depends on its material, length, and cross-sectional area.</p> Signup and view all the answers

<p>Current will flow more easily through a thick wire because it has a larger cross-sectional area, leading to lower resistance.</p> Signup and view all the answers

<p>The current will also decrease to half of its former value.</p> Signup and view all the answers

<p>Alloys are used because they have higher resistivity and can withstand higher temperatures without melting.</p> Signup and view all the answers

<p>Iron is a better conductor than mercury.</p> Signup and view all the answers

<p>Copper is considered the best conductor.</p> Signup and view all the answers

<p>The total resistance increases as more resistors are added in series.</p> Signup and view all the answers

<p>The total resistance decreases when resistors are arranged in parallel.</p> Signup and view all the answers

<p>Increasing the potential difference provides more energy to the charges, leading to an increase in current.</p> Signup and view all the answers

<p>A resistor limits the flow of electric current within a circuit.</p> Signup and view all the answers

<p>The resistance of a conductor depends on its length, cross-sectional area, material, and temperature.</p> Signup and view all the answers

<p>A thicker wire has a larger cross-sectional area, which reduces resistance. The same amount of current encounters less opposition in a thicker wire, allowing it to flow more easily.</p> Signup and view all the answers

<p>The current through the component will also be halved.</p> Signup and view all the answers

<p>Alloys have higher melting points and greater resistance compared to pure metals. This makes them suitable for heating elements.</p> Signup and view all the answers

<p>Mercury is a better conductor than iron. This is because mercury has a lower resistivity compared to iron.</p> Signup and view all the answers

<p>The best conductor is the material with the lowest resistivity value.</p> Signup and view all the answers

<p>The current flowing through each resistor in a series circuit is the same, and it equals the total current in the circuit.</p> Signup and view all the answers

<p>The total resistance in a series circuit is equal to the sum of the individual resistances of the resistors in the circuit.</p> Signup and view all the answers

<p>The sum of the potential differences across each resistor in a series circuit is equal to the total potential difference applied to the circuit.</p> Signup and view all the answers

<p>The total current in a parallel circuit is equal to the sum of the currents flowing through each branch of the circuit.</p> Signup and view all the answers

<p>The resistance of a conductor depends on its material and its dimensions, specifically length and cross-sectional area.</p> Signup and view all the answers

<p>Current flows more easily through a thick wire because it offers less resistance due to its larger cross-sectional area.</p> Signup and view all the answers

<p>The current will decrease to half its former value.</p> Signup and view all the answers

<p>Alloys are used because they can provide greater resistance and thus produce more heat.</p> Signup and view all the answers

<p>Iron is a better conductor than mercury.</p> Signup and view all the answers

<p>Copper is often considered the best conductor among common materials.</p> Signup and view all the answers

<p>The total resistance increases when resistors are connected in series.</p> Signup and view all the answers

<p>The total resistance decreases when resistors are connected in parallel.</p> Signup and view all the answers

<p>Increased temperature typically causes the resistance of a conductor to increase.</p> Signup and view all the answers

<p>Ohm's law states that the current flowing through a conductor is directly proportional to the voltage across it and inversely proportional to its resistance.</p> Signup and view all the answers

<p>The current remains the same through each resistor.</p> Signup and view all the answers

<p>The equivalent resistance is the sum of the individual resistances.</p> Signup and view all the answers

<p>The reading of the ammeter remains unchanged regardless of its position.</p> Signup and view all the answers

<p>The current stops flowing in the circuit.</p> Signup and view all the answers

<p>The current reading remains constant independent of position.</p> Signup and view all the answers

<p>The total resistance is 6 Ω.</p> Signup and view all the answers

<p>Connecting an ammeter in series allows it to measure the total current accurately.</p> Signup and view all the answers

<p>The resistors are connected in series.</p> Signup and view all the answers

<p>The primary characteristic is that the same current flows through each component.</p> Signup and view all the answers

<p>In a parallel connection, three resistors are connected between points X and Y, with each resistor having its own separate path for current to flow. This is different from a series connection, where resistors are connected one after another, forming a single path for current.</p> Signup and view all the answers

<p>The current in Activity 11.4 remains the same regardless of the ammeter's position in the series circuit. This implies that in a series connection, the current is constant throughout the circuit and flows through each resistor with the same value.</p> Signup and view all the answers

<p>The current in each resistor in a series combination is equal, meaning they share the same current value.</p> Signup and view all the answers

<p>The current is the same in every part of a series circuit. This means the same current flows through each resistor in the chain.</p> Signup and view all the answers

<p>Activity 11.4 demonstrates that the current is constant throughout a series circuit, regardless of the ammeter's position. This observation establishes the key characteristic of current flow in a series circuit.</p> Signup and view all the answers

<p>The ammeter reading remains constant because the current in a series circuit is the same at every point. This means the current flowing through each resistor is identical, ensuring the ammeter reading remains unchanged no matter where it is positioned in the circuit.</p> Signup and view all the answers

<p>The key characteristic of current flow in a series circuit is that it is constant throughout the circuit. This means the current has the same value at every point in the series connection.</p> Signup and view all the answers

<p>Based on Activity 11.4, the current flowing through each resistor in a series circuit is identical. The constant current throughout the circuit ensures that each resistor experiences the same current value, regardless of its position in the series chain.</p> Signup and view all the answers

<p>The ammeter's position in the series circuit of Activity 11.4 is not significant for current measurement, as the current remains constant throughout the circuit. The ammeter will always register the same value, regardless of its placement in the series connection.</p> Signup and view all the answers

<p>In a series circuit, the <em>same</em> current flows through each resistor. The equivalent resistance is the <em>sum</em> of the individual resistances: $R_{eq} = R_1 + R_2 + ...$</p> Signup and view all the answers

<p>The total resistance is 1 Ω + 2 Ω + 3 Ω = 6 Ω. Using Ohm's Law (V = IR), the current is 6 V / 6 Ω = 1 A.</p> Signup and view all the answers

<p>The setup consists of three resistors connected in series with a battery, an ammeter, and a plug key. The battery provides voltage, the ammeter measures the current, and the plug key allows for control of the circuit. The ammeter is moved to different positions within the series to show that the current remains the same.</p> Signup and view all the answers

<p>The primary observation in Activity 11.4 is that the ammeter reading remains the same regardless of its position in the series circuit. This indicates that the current is constant throughout the series combination, confirming that the same current flows through each resistor.</p> Signup and view all the answers

<p>In a series circuit, the same current flows through all resistors because there is only one path for the current. In a parallel circuit, each branch has its own current flow, with the total current being the sum of the currents in each branch.</p> Signup and view all the answers

<p>Equivalent resistance simplifies circuit analysis by representing multiple resistors as a single equivalent resistor. This allows us to apply Ohm's Law and other circuit laws to the entire circuit more easily, regardless of the number of individual resistors.</p> Signup and view all the answers

<p>First, calculate the total resistance: 4 Ω + 6 Ω = 10 Ω. Then, use Ohm's Law to find the total current: 12 V / 10 Ω = 1.2 A. Since the current is the same in a series circuit, the current through the 4 Ω resistor is also 1.2 A.</p> Signup and view all the answers

<ol> <li>Christmas light strings often use series connections to ensure that if one bulb burns out, the entire string goes dark. This prevents the entire string from becoming unusable due to a single faulty bulb.</li> <li>A voltage divider uses resistors in series to create different voltage levels within a circuit. This is useful for electronic devices that require different voltages for their components.</li> </ol> Signup and view all the answers