Question

A wire of resistance 12 ohms per metre is bent to form a complete circle of radius 10 cm. The resistance between its two diametrically opposite points, A and B as shown in the figure, is :

A. `6 Omega`
B. `0.6 pi Omega`
C. `3 Omega`
D. `6 pi Omega`

Answer 1

Correct Answer - B
Total resistance of wire `=12 Omega xx 2pi xx 10^(-1)`
`=2.4 pi`
Resistance of each half `=(2.4 pi)/(2)=1.2 pi` and as about diameter both parts are in parallel
`Req. =(1.2)/(2)=0.6 Omega `