1. Two point charges are arranged as shown. Where could a third charge +1.0μC be placed so that the net electrostatic force on it is zero?
a. I only
b. I and II only
c. III only I II III
d. II only -------------○-----------○-------------
e. I and III only +2.0μC -1.0μC


2. The capacitance of a single isolated spherical conductor with radius R is proportional to:
a. R
b. R2
c. 1/R
d. 1/R2
e. None of these

3. A point charge is placed at the center of a spherical Gaussian surface. The flux Φ E is changed:
a. If the sphere is replaced by a cube of the same volume
b. If the sphere is replaced by a cube of one/tenth volume
c. If a point charge is moved off center (but still inside the original sphere)
d. If the point charge is moved just outside the sphere
e. If a second charge is placed just outside the sphere

4. A small conducting spherical shell with inner radius a and outer radius b has total charge +2q. Plot the graph of the potential in terms of q and the distance r from the center for all three regions:
a. r<a
b. a<r<b
c. r>b

5. In a certain region of space the electric potential increases uniformly from north to south and does not vary in any other direction. The electric field:
a. Points north and varies with position
b. Points north and does not vary with position
c. Points south and varies with position
d. Points south and does not vary with position
e. Points east and does not vary with position