A conducting sphere of radius 10 cm has an unknown charge

PHYSICS · Subjective · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

A conducting sphere of radius 10 cm has an unknown charge. If the electric field 20 cm from the centre of the sphere is

1.5 \times 10^3\text{ N/C}

and points radially inward, what is the net charge on the sphere?