A laboratory rule specifies that the electric potential relative to infinity must not…
PHYSICS · Multi-part · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
A laboratory rule specifies that the electric potential relative to infinity must not exceed 2.0kV anywhere inside a working region. A small conducting sphere carrying a charge of +6.0μC is to be mounted at the centre of the region. Use 4πε01=9×109N m2C−2.
(i) Write the formula for the electric potential produced by a point charge at a distance r.
(ii) Calculate the minimum distance from the surface of the sphere at which the potential will be 2.0kV or less.
(iii) If the charge on the sphere were doubled while the safety limit remained the same, state and justify how the minimum allowable distance would change.