question_answer

When a wire of uniform cross-section a, length l and resistance R is bent into a complete circle, resistance between any two of diametrically opposite points will be [CBSE PMT 2005]

A)         \[\frac{R}{4}\]          

B)         \[\frac{R}{8}\]

C)         \[4R\]                           

D)         \[\frac{R}{2}\]

Correct Answer: A

Solution :

                                          Þ \[{{R}_{AB}}=\frac{R/2}{2}=\frac{R}{4}\]