Question

In an experiment, James used the thinnest wire he could find to connect a battery to a light bulb. He found that the bulb lit up dimly. He then changed to thicker wires and repeated his experiment, noticing that the light bulb kept getting brighter. Assuming every wire was made from the same conductor (copper) which of the following explanations is most reasonable? (1 point)

Responses

O A metallic conductor becomes an insulator as it decreases in thickness.


O James must have had a bad connection because the light bulb should have illuminated to the same brightness.


O Thin wires do not allow as much electricity to flow as thicker wires.

O Small items are good insulators, while large items are good conductors.

Answer 1

The most reasonable explanation is:

Thin wires do not allow as much electricity to flow as thicker wires.

This is because electrical resistance is directly proportional to the length of a wire and inversely proportional to its cross-sectional area (thickness). Thinner wires have less cross-sectional area, so they offer more resistance to the flow of electricity. This causes some of the electrical energy to be converted into heat energy, rather than being used to power the light bulb, resulting in dim illumination.

As James switched to thicker wires, the cross-sectional area of the wire increased, reducing the resistance and allowing more electricity to flow to the light bulb. This caused the bulb to illuminate brighter, as more of the electrical energy was converted into light energy.

The other options presented are not supported by the laws of electricity and are therefore not reasonable explanations.