AP Physics C: Electricity and Magnetism Flashcards: Electric Power
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 10 cards to help you master important concepts.
What is the fundamental equation for calculating electric power in a circuit element?
The fundamental equation for power is $P=I\Delta V$, where I is the current and $\Delta V$ is the electric potential difference.
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What is the fundamental equation for calculating electric power in a circuit element?
The fundamental equation for power is $P=I\Delta V$, where I is the current and $\Delta V$ is the electric potential difference.
In the context of an electric circuit, what does 'power' describe?
Power describes the rate of energy transfer into, out of, or within an electric circuit.
Using the relationship $P=I^{2}R$, how does the power dissipated by a resistor change if the current through it is doubled?
Since power is proportional to the square of the current, doubling the current will cause the power dissipated to increase by a factor of four.
If two lightbulbs are in a circuit and Bulb A dissipates more power than Bulb B, which bulb is brighter?
Bulb A will be brighter because the brightness of a lightbulb increases with the power it dissipates.
Define electric power based on the rate of energy change.
Electric power is the rate at which energy is transferred, converted, or dissipated by an element in an electric circuit.
What is the equation for electric power expressed in terms of current (I) and resistance (R)?
The equation for power derived in terms of current and resistance is $P=I^{2}R$.
Using the relationship $P=\frac{\Delta V^{2}}{R}$, how does the power dissipated by a resistor change if the potential difference across it is doubled?
Because power is proportional to the square of the potential difference, doubling the potential difference will cause the power dissipated to increase by a factor of four.
How is the power dissipated by a lightbulb related to its brightness?
The brightness of a lightbulb increases with the power it dissipates. Therefore, power can be used to qualitatively predict a bulb's brightness.
What two quantities determine the rate at which energy is transferred by a circuit element?
The rate of energy transfer (power) depends on the current in the element and the electric potential difference across it.
What is the equation for electric power expressed in terms of potential difference ($\Delta V$) and resistance (R)?
The equation for power derived in terms of potential difference and resistance is $P=\frac{\Delta V^{2}}{R}$.