A spherical conductor of radius 2 cm is uniformly charged with 3 nC. What is the electric field at a distance of 3 cm from the centre of the sphare ?

Options

A. `3xx10^(4)V m^(-1)`
B. `3xx10^(6)V m^(-1)`
C. `3xx10^(-4) V m^(-1)`
D. `3 V m^(-1)`

Answer

A

Explanation

Here,
`Q=3 nC= 3xx10^(-9)C`
`R=2 cm = 2 xx 10^(-2)m`
At a point 3 cm from the centre,
i.e., `r=3 cm = 3 xx10^(-2)m`
`:.` Electric field,
`E=(1)/(4 pi epsilon_(0))(Q)/(r^(2))=(9xx10^(9)xx3xx10^(-9))/((3xx10^(-2))^(2))`
`=3xx10^(4)V m^(-1)`