A closed spherical surface of radius is kept in vacuum
PHYSICS · Multi-part · CBSE · Physics · Electric Charges and Fields · Electric Charges and Fields
Problem
A closed spherical surface of radius 15cm is kept in vacuum. A point charge of +2μC is placed at its centre while another point charge of −3μC is kept at a distance of 40cm from the centre (outside the sphere).
(i) Calculate the net electric flux through the spherical surface.
(ii) If the external charge is moved until it just touches the surface from outside, what change, if any, will occur in the electric flux? Give reason.
(iii) Determine the magnitude and sign of an additional point charge that must be placed inside the sphere so that the total electric flux through the surface becomes zero while keeping the original two charges in their initial positions.