Answer:
r = 6.6 x 10³ m = 6600 m
Step-by-step explanation:
The potential at a distance from a charged sphere can be given as follows:

where,
r = distance = ?
k = Colomb Constant = 9 x 10⁹ Nm²/C²
q = charge on sphere = 3.3 C
V = potential = 4.5 MV = 4.5 x 10⁶ V
Therefore,

r = 6.6 x 10³ m = 6600 m