A small conducting spherical shell with inner radius a and outer radius b is con
ID: 1525572 • Letter: A
Question
A small conducting spherical shell with inner radius a and outer radius b is concentric with a larger conducting spherical shell with inner radius c and outer radius d. The inner shell has a total charge of -2q and the outer shell has a total charge of +4q.
Select True or False for the following statements.
The total charge on the inner surface of the large shell is -6q.
The total charge on the inner surface of the small shell is zero.
The electric field in the region c < r < d is zero.
The electric field in the region r > d is zero.
The total charge on the outer surface of the large shell is +2q.
The total charge on the outer surface of the small shell is -6q.
The electric field in the region r < a is zero.
Explanation / Answer
field inside conductor is always zero.
and from Gauss Law,
E. A =Qin / e0
E = 0 hence Qin = 0
for c < r < d
Qin = Q_inner_shell + Qc = 0
-2q + Qc = 0
Qc = 2q .....charge on inner surafce of large shell
for a < r < b
Qin = Qa = 0 ...inner surface of small shell
Qa + Qb = -2q
Qb = -2q ....charge on outer surface of small shell
Qc + Qd = 4q
Qd = 4q - 2q = 2q ..charge on outer surfdace of large shell
E = zero { r < a , a < r < b , c < r < d }
Ans: F T T F T F T