A) 2R
B) R/2
C) R/4
D) R/S
Correct Answer: C
Solution :
Resistance of wire \[(R)=\rho \frac{l}{A}\] If wire is bent in the middle then\[l'=\frac{l}{2'}A'=2A\] \[\therefore \]New resistance, \[R'=\rho \frac{l'}{A'}\] \[=\frac{\rho \frac{l}{2}}{2A}=\frac{\rho l}{4A}=\frac{R}{4}.\]
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