A non-conducting thin disc of radius R rotates about its axis with an angular velocity `omega`. The surface charge density on the disc varies with the distance r from the centre as `sigma(r)=sigma_(0)[1+((r)/(R))^(beta)]`, where `sigma_(0)` and `beta` are constants. If the magnetic induction at the center is `B=((9)/(10))mu_(0)sigma_(0)omegaR`, the value of `beta` is

Options

A. `1/4`
B. 4
C. `1/2`
D. 2

Answer

C