1. The problem statement, all variables and given/known data A 30 cm diameter metal sphere hangs from a thread in the middle of a very large room. So its surroundings are essentially at infinity. If the electric field at tis surface is equal to the break down strength of air 3MV/m, what is the absolute potential at the center of the sphere? A) 450 kV B) 150 kV C) 300 kV D) 0 The answer is from what i've searched online is A 2. The attempt at a solution The Electric FIeld at the surface is 3,000,000 V/m so kQ/r2=3,000,000 The only unknown is charge and solving we get Q=3*106*r2/k where (k=1/4pi epsilon nought) so potential at the centre =kQ/r=9* 105 V which is wrong so help please..