Physics Review Question

Unit: Electricity and Magnetism
Year: 1995 Question#: 27
Question: The diagram below shows a circuit in which a copper wire connects points A and B. The electrical resistance between points A and B can be decreased by:


(1 ) replacing the wire with a thicker copper wire of the same length
(2 ) replacing the wire with a longer copper wire of same thickness
(3 ) increasing the temperature of the copper wire
(4 ) increasing the potential difference supplied by the battery

What is this question really asking?




Explanation by: Dustin C.

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Answer 1
replacing the wire with a thicker copper wire of the same length

CORRECT

This answer is correct because with a thicker copper wire there is a wider path for the electrons to flow and therefore it would decrease the electrical resistance. return to top























Answer 2
replacing the wire with a longer copper wire of the same length

INCORRECT


This answer is incorrect because a longer copper wire would increase the resistance because there would be a longer path for the electrons to flow through return to top



























Answer 3
increasing the temperature of the copper wire

INCORRECT


This answer is incorrect because increasing the temperature would make the molecules jump around a lot which would prevent the electrons from flowing through the wire smoothly, so it would not decrease the resistance. return to top


























Answer 4
increasing the potential difference supplied by the battery

INCORRECT


This answer is sort of like number one because it increases the current but it does not do this by decreasing the electrical resistance. return to top


























What's this question really asking?

This question is asking how, in the diagram above, the electrical resistance could be decreased between the two points by... return to top

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