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A small conducting spherical shell with inner radius a and outer radius b is con

ID: 2000668 • 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 -1q and the outer shell has a total charge of +4q.

True/False

T/F The total charge on the outer surface of the small shell is -5q.
T/F The total charge on the outer surface of the large shell is +3q.
T/F The total charge on the inner surface of the small shell is -5q.
T/F The radial component of the electric field in the region c < r < d is given by -1q/(40r2).
T/F The electric field in the region r > d is zero.
T/F The total charge on the inner surface of the large shell is +1q.
T/F The electric field in the region r < a is zero.

Explanation / Answer

The total charge on the outer surface of the small shell is -5q.

Flase: The total charge on the outer surface of the small shell is –1q, since the inner sphere has a charge of -1q


The total charge on the outer surface of the large shell is +3q.

Flase: The total charge on the outer surface of the small shell is +4q, since the outer sphere has a charge of +4q


The total charge on the inner surface of the small shell is -5q.

Flase: The total charge on the outer surface of the small shell is +1q, since the inner sphere has a charge of -1q and +1q will be induced on inner surface of the small shell.


The radial component of the electric field in the region c < r < d is given by -1q/(40r2).

True: E inside the conductor = 0


The electric field in the region r > d is zero.

Flase: Qnet at r > d = (-1q + 4q) = +3q hence E will non zero. E = 3q/(40r2).


The total charge on the inner surface of the large shell is +1q.

True: The total charge on the outer surface of the small shell is +1q, since the inner sphere has a charge of -1q and +1q will be induced on inner surface of the small shell.


The electric field in the region r < a is zero.

True: electric field inside the small sphere = 0 since Qnet here = (-1q+1q) =0