A wire of resistance `0.5 ohm m^(-1)` is bent into a circle of radius `1m`. The same wire is connected across a diameter `AB` as shown in fig. The equivalent resistance is

Options

A. `pi`ohm
B. `pi(pi+2)ohm`
C. `pi//(pi+4)ohm`
D. `(pi+4)ohm`

Answer

C

Explanation

`(1)/(R_(AB))`=`(1)/(0.5pi)+(1)/(1)+(1)/(0.5pi)` `rArr` `R_(AB)=(pi)/((pi+4))Omega`