Physicsmedium · Past Paper
Resistance of a wire of length L and area A is R. If another wire of same material has length 2L and area 2A, its resistance will be:
AR
B2R
C4R
DR/2
✓ Correct Answer: A — R
R' = ρ(2L)/(2A) = ρL/A = R. The changes in length and area cancel each other out.
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