Practise IB Physics HL D.2.14 Electric potential energy and work with questions connecting electric fields, potential difference and work.
A metal sphere is charged positively and placed far away from other charged objects. The electric potential at a point on the surface of the sphere is 53.9 kV .
The electric potential at a point a distance 2.8 m from the centre of the sphere is 7.71 kV . Determine the radius of the sphere.
use of V r= constant 0.40 m
Marking guidance:
Allow [1] max if r+2.8 used to get 0.47 m .
Allow [2] marks if they calculate Q at one potential and use it to get the distance at the other potential.