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AP® Physics 1 & 2

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Potentiometer

APPH12-4LLLJN

Created for Albert.io. Copyright 2016. All right reserved.

The diagram above shows a potentiometer connected to a battery of fixed voltage and a light bulb. The potentiometer has three leads. Two leads connect to the ends of a long, curved resistor; and the third lead connects to a rotating central wire that can intersect the curved resistor at various angles.

Where the central wire meets the curved resistor represents a junction in the circuit.

Which of the following statements below best describes what will happen to the light bulb as the angle of the central wire increases?

A

The light will grow brighter as the angle increases because the two resistors in parallel will lower the total resistance.

B

The light bulb will grow brighter as the angle increase because the length of a resistor is inversely proportional to its resistance.

C

The light bulb will grow dimmer as the angle increases because more potential is lost across the curved resistor and less potential is available to be applied across the light bulb.

D

The light will remain constant in brightness as the angle increases because the resistance of the light is not affected by the position of the potentiometer.