Question

A charge $q$ is placed at point $\text{O}$ in a cavity in a spherical uncharged conductor. Point S is outside the conductor. If $q$ is displaced from $\text{O}$ towards $\text{S}$ such that it is still inside the cavity, then electric field at $\text{S}$ will

• A. decrease
• B. increase
• C. first increase and then decrease
• D. remain unchanged

Answer 1

The correct option is D remain unchanged

The spherical uncharged conductor will show electrostatic shielding and will not allow electric field lines from charge $q$ to penetrate it. Thus, there will be no effect of electric field due to $q$ at point $\text{S}$. Hence, even on moving the charge inside the cavity the electric field at $\text{S}$ will remain uncharged.