Question

Figure shows a point charge of `0.5 xx 10^(-6)` C at the center of the spherical cavity of radius 3 cm of a piece of metal. The electric field at

A. A (2 cm from the charge ) is 0.
B. A (2 cm from the charge ) is `1.125 xx 10^7 NC^(-1)`
C. B (5 cm from the charge ) is 0
D. B (5 cm from the charge ) is `1.8 xx 10^6 NC^(-1)`

Answer 1

Correct Answer - B::C
At `A, E = ( 9 xx 10^(9) xx 0.5 xx 10^(-6))/((2 xx 10^(-2))^(2)) = 1.125 xx 10^(7) NC^(-1)`
At `B , E = 0` , because in a metal , electric field is zero.