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 piohm
B. 3 ohm
C. 6 piohm
D. 6 ohm

Answer

D

Explanation

`vec(P)(t) = A[hat(i) cos (kt) - hat(j) sin (kt)]`
`vec(F) = (dvec(p))/(dt) = Ak [- hat(i) sin (kt) - hat(j) cos (kt)]`
`vec(F).vec(p) = Fp cos theta` But`vec(F).vec(p) = 0 rArr cos theta = 0 rArr theta = 90^(@)`