10A

YOUR ANSWER:

The specific resistance of a material is the resistance of any amount of

(From P1-21A)

that material at 20 degrees centigrade.

No. You have the right temperature but the rest of the answer is wrong. Remember, resistance is

determined by the length and cross-sectional area too. What this answer implies is that the resistance of a copper

wire one foot long and one inch in diameter would be the same as the resistance of a copper wire ten feet long and

two inches in diameter, and we both know that this isn't true. Specific resistance is the resistance of a particular

amount of a material at a temperature of 20 degrees centigrade. Now go back to Page 1-21A and choose the

correct answer.

10B

YOUR ANSWER:

The resistance would stay the same.

(From P1-2A)

Maybe you didn't understand the question. If a conductor four inches long and one inch in diameter had a

resistance of 8 ohms and we stretched it out to 8 inches, it would be longer. Since the resistance varies directly

with the length of a conductor and we made it longer, the resistance would have to increase. Also, when we

stretched it out, its diameter decreased. Since the resistance varies inversely with the cross-sectional area and we

decreased the cross-sectional area, we caused the resistance to increase. Go back to Page 1-2A and choose

another answer.

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