Podcast
Questions and Answers
Electric power is the rate at which electrical energy is transferred by an electric circuit expressed in ______ (W) or kilowatts (kW)
Electric power is the rate at which electrical energy is transferred by an electric circuit expressed in ______ (W) or kilowatts (kW)
watts
The formula to calculate power in an electric circuit is P = ______
The formula to calculate power in an electric circuit is P = ______
VI
Ohm's law states that the voltage across a conductor is directly proportional to the ______ through the conductor
Ohm's law states that the voltage across a conductor is directly proportional to the ______ through the conductor
current
Increase in voltage applied to a resistive load causes more ______ to flow through the load
Increase in voltage applied to a resistive load causes more ______ to flow through the load
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The electrical energy consumed by an appliance depends on how much work is done per ______ unit
The electrical energy consumed by an appliance depends on how much work is done per ______ unit
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A 60 Watt light bulb consumes 60 Joules of energy within one ______ of being switched on
A 60 Watt light bulb consumes 60 Joules of energy within one ______ of being switched on
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Study Notes
Understanding Electric Power and Circuits
Electric power is the rate at which electrical energy is transferred by an electric circuit expressed in watts (W) or kilowatts (kW). It's calculated using the formula [P = VI] where (P) represents the power, (V) represents voltage, and (I) represents current. To clarify this concept further, let's consider a few examples:
Ohm's Law
Ohm's law states that the voltage across a conductor between two points is directly proportional to the current through the conductor, when measured under constant temperature conditions. In other words, if you increase the voltage applied to a resistive load, it will cause more current to flow through the load. This relationship can be represented mathematically as [V=IR,] where (V) represents the voltage, (I) represents the current, and (R) represents the resistance of the circuit.
Electrical Energy
The electrical energy consumed by an appliance depends on how much work is done per time unit. If you plug your fluorescent light into an outlet, it uses up some electricity every second to emit light. This consumption of electricity measures its power dissipation or usage. For instance, a 60 Watt light bulb consumes 60 Joules of energy within one second of being switched on.
Resistance and Voltage Drop
In a balanced three-phase system with perfect balance in phase voltages, each phase carries equal current and hence has equal voltage drop. However, when there is an unbalance in the phases, different levels of voltage drops occur due to differences in resistances among the conductors.
Time Interval for Measuring Power
For measuring electrical power over a certain interval of time, we need to multiply the power value by the duration of the interval in seconds. A common device used for measuring power is a wattmeter, also known as a kilowatt hour meter.
Understanding these fundamentals of electric power and circuits allows us to grasp how electricity flows through a network, what factors affect the efficiency of transferring power from source to destination, and how to ensure safety while working with electrical systems.
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Description
Explore the concepts of electric power, Ohm's Law, electrical energy, resistance, voltage drop, and time interval measurements in circuits. Enhance your understanding of how electric circuits transfer energy and the factors influencing their efficiency.
