Podcast
Questions and Answers
What is the formula for applying Ohm's law to the entire circuit?
What is the formula for applying Ohm's law to the entire circuit?
- R=VI
- I=R/V
- I=VR
- V=IR (correct)
What is the formula for the total resistance of the combination of resistors joined in series?
What is the formula for the total resistance of the combination of resistors joined in series?
- Rs = R1 + R2 + R3 (correct)
- Rs = R1 / R2 / R3
- Rs = R1 × R2 × R3
- Rs = R1 - R2 - R3
What is the total resistance of the circuit in the example problem?
What is the total resistance of the circuit in the example problem?
- 6 Ω
- 20 Ω
- 24 Ω (correct)
- 4 Ω
What is the voltage across the electric lamp and conductor in the example problem?
What is the voltage across the electric lamp and conductor in the example problem?
What is the current through the circuit in the example problem?
What is the current through the circuit in the example problem?
What is the formula used to calculate the current through the circuit?
What is the formula used to calculate the current through the circuit?
What is the resistance of the electric lamp in the example problem?
What is the resistance of the electric lamp in the example problem?
What is the total potential difference across the two terminals of the battery in the example problem?
What is the total potential difference across the two terminals of the battery in the example problem?
What gases are usually used to fill bulbs to prolong the life of the filament?
What gases are usually used to fill bulbs to prolong the life of the filament?
What is the primary function of a fuse in electric circuits?
What is the primary function of a fuse in electric circuits?
What is the characteristic of the metal or alloy used to make a fuse wire?
What is the characteristic of the metal or alloy used to make a fuse wire?
What is the unit of electric power?
What is the unit of electric power?
What is the rate at which electric energy is consumed in an electric circuit?
What is the rate at which electric energy is consumed in an electric circuit?
Why is a 5 A fuse used for an electric iron that consumes 1 kW electric power?
Why is a 5 A fuse used for an electric iron that consumes 1 kW electric power?
What is the term used to describe the rate of doing work?
What is the term used to describe the rate of doing work?
What is the effect of excessive current flowing through a fuse wire?
What is the effect of excessive current flowing through a fuse wire?
What is the direction of electric current in a circuit?
What is the direction of electric current in a circuit?
What is the unit of electric current?
What is the unit of electric current?
What is the formula to calculate the amount of electric charge?
What is the formula to calculate the amount of electric charge?
What is the amount of electric charge that flows through the circuit in the example?
What is the amount of electric charge that flows through the circuit in the example?
What is the average speed of electrons in a conductor?
What is the average speed of electrons in a conductor?
How do electrons move in a perfect solid crystal?
How do electrons move in a perfect solid crystal?
What is the role of the plug key in the circuit?
What is the role of the plug key in the circuit?
What is the purpose of an ammeter in the circuit?
What is the purpose of an ammeter in the circuit?
What is the order of the drift speed of electrons in a typical copper wire carrying a small current?
What is the order of the drift speed of electrons in a typical copper wire carrying a small current?
Why does an electric bulb light up immediately when we turn the switch on?
Why does an electric bulb light up immediately when we turn the switch on?
What is necessary for the flow of charges in a conducting metallic wire?
What is necessary for the flow of charges in a conducting metallic wire?
What generates the potential difference across the terminals of an electric cell?
What generates the potential difference across the terminals of an electric cell?
What is the role of gravity in the flow of charges in a conducting metallic wire?
What is the role of gravity in the flow of charges in a conducting metallic wire?
What is the purpose of a battery in a conducting circuit?
What is the purpose of a battery in a conducting circuit?
What is the analogy used to describe the flow of charges in a conducting metallic wire?
What is the analogy used to describe the flow of charges in a conducting metallic wire?
What happens when a cell is connected to a conducting circuit element?
What happens when a cell is connected to a conducting circuit element?
What is the potential difference across the resistor when the current is 2.0 A?
What is the potential difference across the resistor when the current is 2.0 A?
A 12 V battery is connected across an unknown resistor, and a current of 2.5 mA flows. What is the resistance of the resistor?
A 12 V battery is connected across an unknown resistor, and a current of 2.5 mA flows. What is the resistance of the resistor?
A battery of 9 V is connected in series with resistors of 0.2 Ω, 0.3 Ω, 0.4 Ω, 0.5 Ω, and 12 Ω, respectively. What is the current that would flow through the 12 Ω resistor?
A battery of 9 V is connected in series with resistors of 0.2 Ω, 0.3 Ω, 0.4 Ω, 0.5 Ω, and 12 Ω, respectively. What is the current that would flow through the 12 Ω resistor?
How many 176 Ω resistors are required to carry 5 A on a 220 V line?
How many 176 Ω resistors are required to carry 5 A on a 220 V line?
How can three resistors, each of resistance 6 Ω, be connected to have a resistance of 9 Ω?
How can three resistors, each of resistance 6 Ω, be connected to have a resistance of 9 Ω?
Several electric bulbs are rated 10 W and are designed to be used on a 220 V electric supply line. What is the maximum number of lamps that can be connected in parallel with each other across the two wires of 220 V line if the maximum allowable current is 5 A?
Several electric bulbs are rated 10 W and are designed to be used on a 220 V electric supply line. What is the maximum number of lamps that can be connected in parallel with each other across the two wires of 220 V line if the maximum allowable current is 5 A?
A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What is the current in the parallel case?
A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What is the current in the parallel case?
Two lamps, one rated 100 W at 220 V, and the other 60 W at 220 V, are connected in parallel to electric mains supply. What is the total current drawn from the line if the supply voltage is 220 V?
Two lamps, one rated 100 W at 220 V, and the other 60 W at 220 V, are connected in parallel to electric mains supply. What is the total current drawn from the line if the supply voltage is 220 V?
Study Notes
Electric Circuits and Current
- Electric current flows in a circuit from the positive terminal of the cell to the negative terminal through the circuit components (e.g., bulb and ammeter).
- A schematic diagram of an electric circuit consists of a cell, electric bulb, ammeter, and plug key.
Electric Charge and Flow
- The flow of electric charge is similar to the flow of water, requiring a pressure difference (electric potential difference) to occur.
- In a conducting metallic wire, electrons move only if there is a potential difference along the conductor.
- The potential difference is produced by a battery, which generates a potential difference across its terminals even when no current is drawn.
Electric Current and Drift Speed
- The motion of electrons in a conductor is different from that of charges in empty space.
- When a steady current flows through a conductor, the electrons move with a certain average drift speed, which is very small (e.g., 1 mm s-1 in a typical copper wire).
Electric Potential and Potential Difference
- Electric potential difference (or voltage) is the driving force behind electric current flow.
- Applying Ohm's law to the entire circuit, we have V = IR, where V is the potential difference, I is the current, and R is the resistance.
Resistors in Series
- When several resistors are connected in series, the total resistance of the combination (Rs) equals the sum of their individual resistances (R1, R2, R3, etc.).
- The total resistance of the combination is greater than any individual resistance.
Electric Power and Energy
- Electric power is the rate of consumption of energy, which is also the rate at which electric energy is dissipated or consumed in an electric circuit.
- The values of current I flowing in a given resistor for the corresponding values of potential difference V across the resistor can be used to plot a graph and calculate the resistance of the resistor.
Applications of Electric Circuits
- Electric lamps are usually filled with chemically inactive nitrogen and argon gases to prolong the life of the filament.
- Joule's heating is used in fuses, which protect circuits and appliances by stopping the flow of any unduly high electric current.
- Electric power is used in various applications, such as electric irons, which consume a certain amount of power when operated at a specific voltage.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers the basics of electric circuits, including the flow of electric current and the components of a circuit. Test your understanding of electric circuits and their components.
