A spherical conductor of radius 0.12 m has a charge of `1.6 xx 10^-7C` distributed uniformaly on its surface. What is the electric field (i) Inade the sphere (ii) on the sphere (iii) at a point 0.18 m from the centre of the sphere?

Explanation

Radius of a sphere r = 0.12 m,
Charge of a sphere `q= 1.6 xx10^-7C`.
(i) Electric field inside the sphere = 0
(ii) Electric field on the sphere
`E= 1/(4piepsilon_0)q/r^2`
`= 9xx10^9xx(1.6xx10^-7)/(12xx10^-2)^2`
`= (9xx1.6)/(12xx12)xx10^(9-7+4)`
`= 14.4/144 xx 10^6`
`= 0.1 xx 10^6 = 10^5 NC^-1`
(iii) Electric field at a point 0.18 m from the centre of the sphere
`E= 1/(4piepsilon_0)q/r^2`
`= 9xx10^9xx (1.6xx10^-7)/(18xx10^-2)^2`
`= (9xx10^91.6xx10^-7)/(18xx18)xx10^4`
`=0.4/9 xx10^(9-7+4)`
`= 0.4/9 xx 10^6 = 0.0444 xx10^6`
`=4.44xx10^4NC^-1`
Electric field inside the sphere = 0
Electric field on the sphere = `10^5NC^-1`
Electric field at a point 0.18 m from the centre of the sphere `= 4.44 xx10^4NC^-1`