A wire of resistance `12 Omega m^(-1)` is bent to from a complete circle of radius `10 cm`. The resistance between its two diametrically opposite points, `A` and `B` as shown in the figure, is

Options

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

Answer

A

Explanation

Length of wire (l) `=2pir = 0.2 pi m`

Resistance of wire = `12 xx 0.2pi = 2.4 Omega`
Resistance of each semicircle `=1.2 Omega`
`R_(eq) = (1.2 pi)/2 = 0.6 pi Omega`