Single Answer MCQ
Q-00019351
If the length of a conductor is doubled and its area of cross-section is halved, what will happen to its resistance?
1
Remain the same
2
Double
3
Increase four times
4
Increase by a factor of eight
Answer and Solution
Answer
D. Increase by a factor of eight
Solution:
Using the formula R = ρ(l/A), if length is doubled (2l) and area is halved (A/2), the new resistance becomes (2ρl) / (A/2) = 4ρl/A, which is four times the original resistance.
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