When the length and area of cross-section both are doubled, then its resistance:
Correct answer: B. Will remain the same
- A. Will become half
- B. Will remain the same
- C. Will be doubled
- D. Will become four times
Explanation
Resistance is given by R = ρL/A. If the new length is L' = 2L and the new area is A' = 2A, the new resistance is R' = ρ(2L)/(2A) = ρL/A = R. The resistance remains unchanged.
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