Some of the equipotential surfaces of the magnetic scalar potential the magnitude of magnetic field B at a point in the region is

Options

A. `10^(-3) T`
B. `(2)/sqrt(3)xx10^(-4)T`
C. `2xx10^(-4)` T
D. `sqrt(3)/(2)xx10^(-4)T`

Answer

C

Explanation

Field B will be normal to the equipotential lines thus angle between field and x axis is `60^(@)` or `120^(@)`
Now `B=(dV)/(dr)`
Even for `theta=120^(@)` the magnitude of field is same