COnducting sphere physics problem: A conducting sphere has a radius of 1.55 m an
ID: 1316794 • Letter: C
Question
COnducting sphere physics problem:
A conducting sphere has a radius of 1.55 m and carries a positive surplus charge of 35.0 mC. A protective layer of barium titanate is applied to the surface of the sphere to make It safe for laboratory workers nearby. Safety considerations dictate that the potential difference between the surface of the conductor and the outside of the nonconductive layer must be 20,000 V (though this is by no means safe under all conditions). Part A How thick must the protective layer be?Explanation / Answer
potential due to sphere=kQ/R
Q=35*10-3 C
R=1.55 m
V=9*109*35*10-3/1.55=203.22*106 V
but we are given
V1=20,000
let it be at distance=r from teh center
V1=kQ/r
r=kQ/V1=9*109*35*10-3/20,000
r=15750 m
thickness of layer=(15750-1.55)m