AP Physics C Electricity : Calculating Current

Study concepts, example questions & explanations for AP Physics C Electricity

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Example Questions

Example Question #1 : Current

A lamp has a  bulb. If the house wiring provides  to light up that bulb, how much current does the bulb draw?

Possible Answers:

Correct answer:


The formula for power is ,and we are given the following values.

Solve for the current, .

Example Question #1 : Calculating Current

A particle accelerator with a radius of 500 meters can have up to  protons circulating within it at once.

How fast must the protons in the accelerator move in order to produce a current of 1A?

Possible Answers:

Correct answer:


The current produced is the total charge that circulates the particle accelerator per unit time.

We calculate this by the equation:

 is the number of protons,  is the charge per proton,  is the velocity of each proton, and  is the radius of the particle accelerator.

Using the given current, we then solve for the velocity:

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