A point charge `Q` is placed outside a hollow spherical conductor of radius `R` , at a distance `r (r gt R)` from its centre `C` . The field at `C` due to the inducted charges on the conductor is

Options

A. zero
B. `k(Q)/((r - R)^(2))`
C. `k (Q)/(r^(2))` , directed towards `Q`
D. `k(Q)/(r^(2))` , directed away from `Q`

Answer

3

Explanation

The electric field at centre is zero . Due to `Q` , electric field will be `k(Q)/(r^(2))` away from `Q`, to balance this field , induced charge will produce electric field `k Q//r^(2)` towards `Q` , so that net electric field is zero.