AIPMT PRELIMS2004Physics-Electricity
AIPMT PRELIMS 2004 Physics Resistance and Resistivity MCQ Question
Type: MCQ-conceptual-Medium-Class 12
The electric resistance of a certain wire of iron is R. If its length and radius are both doubled, then:-
A
The resistance will be halved and the specific resistance will remain unchanged
B
The resistance will be halved and the specific resistance will be doubled
C
The resistance and the specific resistance, will both remain unchanged
D
The resistance will be doubled and the specific resistance will be halved
Correct Answer
Option A
Detailed Explanation
Resistance R is proportional to length and inversely proportional to the cross-sectional area. Doubling both length and radius results in halving the resistance.
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