1. Two charges are separated by a distance d and exert mutual attractive forces of F ob each other. If the charges are separated by a distance of d/3, what are the new mutual forces?
a. F/3
b. F/9
c. 3F
d. 9F
2. A +4.0 C charge is at the origin and +9.0 C charge is at x=4.0 m. Where on the x-axis can a third charge be placed so the net force on it is zero?
a. 0.5 m from +4.0 C
b. 0.6 m from +4.0 C
c. 1.6 m from +4.0 C
d. 2.4 m from +4.0 C
3. An electron and a proton are separated by a distance of 1.0 m. What happens to the magnitude of the force on the proton if a second electron is placed next to the first electron?
a. it quadruples
b. it doubles
c. it will not change
d. it goes to zero
4. Sphere A carries a net positive charge, and sphere B is neutral. They are placed near each other on an insulated table. Sphere B is briefly touched with a wire that is grounded. Which statement is correct?
a. Sphere B remains neutral.
b. Sphere B is now positively charged.
c. Sphere B is now negatively charged.
d. The charge on sphere B cannot be determined without additional information.
5. A proton, initially at rest is accelerated through an electric potential difference of 500 V. What is the kinetic energy of the proton?
a. 500 J
b. 8.0x10-17 J
c. 1.6x10-19 J
d. zero
6. It takes 10 J of energy to move 2.0 C of charge from point A to point B. What is the potential difference between points A and B?
a. 20 V
b. 0.20 V
c. 5.0 V
d. 0.5 V
7. Consider a uniform electric field of 50 N/C directed toward the east. If the voltage measured relative to ground at a given point in the field is 80 V, what is the voltage at a point 1.0 m directly east of the point?
a. 15 V
b. 30 V
c. 90 V
d. 130 V
8. The absolute potential at a distance of 2.0 m from a positive point charge is 100 V. What is the absolute potential 4.0 m away from the same point charge?
a. 25 V
b. 50 V
c. 200 V
d. 400 V
9. The plates of a parallel-plate capacitor are maintained with constant voltage by a battery as they are pulled apart. During this process, the amount of charge on the plates must
a. increase
b. decrease
c. remain constant
d. either decrease or increase. There is no way to tell from the information given.
10. The length of a wire is doubled and the radius is doubled. By what factor does the resistance change?
a. four times as large
b. twice as large
c. half as large
d. quarter as large
11. The resistivity of most common metals
a. remains constant over wide temperature ranges
b. increases as the temperature increases
c. decreases as the temperature increases
d. varies randomly as the temperature increases.
12. What is the nominal resistance of a 100 W light bulb designed to be used in a 120-V circuit?
a.12.0
b.144
c.1.2
d. 0.83
13. A parallel-plate capacitor is connected to a battery and becomes fully charged. The capacitor is then disconnected, and the separation between the plates is increased in such a way that no charge leaks off. The energy stored in this capacitor has
a. increased
b. decreased
c. not changed
d. become zero
14. A parallel plate capacitor is constructed with plate area of 0.40 m2 and a plate separation of 0.1 mm. How much charge is stored on it when it is charged to a potential difference of 12 V?
a. 0.21 C
b. 0.42 C
c. 0.63 C
d. 0.84 C
15. A negatively charged rod is brought near one end of an uncharged metal bar. The end of the metal bar farthest from the charged rod will be charged
a. positive
b. negative
c. neutral
d. none of the above