Download Chapter 12: Electrostatic Phenomena

Chapter 12: Electrostatic Phenomena
1. Consider a proton and an electron placed near one another with no other objects close by.
They would
A. accelerate away from each other.
B. remain motionless.
C. accelerate toward each other.
D. be pulled together at constant speed.
E. move away from each other at constant speed.
2. Compared to the magnitude of the charge on a proton, the magnitude of the electrical charge
carried by an electron is
A. about the same.
B. exactly the same.
C. is only ½ as large.
D. is only ⅓ as large.
3. Two equal positive charges are near each other. If we increase the amount of charge on just
one of them, then
A. both charges feel an increased electrical force.
B. only smaller charge feels an increased electrical force.
C. the electric field felt by both charges increases.
D. the electric field felt by the smaller charge increases.
E. Both answers A and D
4. A strip of fur is rubbed against a hard rubber rod. The rod thereby acquires a negative charge
because
A. frictional forces create electrons.
B. rubbing caused electrons to move from the fur to the rod.
C. friction caused protons to be removed from the rod.
D. electrons from the air molecules are transferred to the rod.
5. If the distance between two spherical charged objects increases by a factor of two, then the
electrical force between the objects
A. decreases by a factor of four.
B. is half as big.
C. does not change.
D. doubles.
E. increases by a factor of four.
6. A metallic object has a net charge on it. For steady state conditions, the excess charge is
located
A. on the bottom of the object .
B. on the surface of the object.
C. near the side closest to the North magnetic pole.
D. at the center of mass of the object.
E. at the top of the object.
7. After a glass rod is rubbed with a nylon cloth
A. the rod will have a positive charge and the cloth negative.
B. both the rod and cloth will have a positive charge.
C. the rod will have a negative charge and the cloth positive.
D. both the rod and cloth will have a negative charge.
E. the rod will have a negative charge and the cloth will be neutral.
8. A rubber rod is rubbed with fur, so that the fur becomes positive. The rod is then used to
charge an electroscope. The charge on the electroscope will be
A. positive if charged by contact.
B. positive if charged by induction.
C. neutral.
D. negative if charged by induction.
9. A positively charged rod is brought close to an uncharged electroscope. While the rod is
close, one’s finger touches the far side of the metal ball on the electroscope. The finger is
removed and then the rod is taken away. The electroscope is
A. positively charged.
B. negatively charged.
C. uncharged.
10. A negatively charged rod is brought close to an uncharged electroscope. While the rod is
close one’s finger touches the far side of the metal ball on the electroscope. After the charged
rod has been removed the finger is removed. The electroscope is
A. positively charged.
B. negatively charged.
C. uncharged.
11. Comparing the electrostatic force and the gravitational force we can say that
A. both have the same dependence on distance, both involve attraction and repulsion but the
gravitational force is stronger.
B. both have the same dependence on distance, both involve attraction and repulsion but the
electrostatic force is stronger.
C. both have the same dependence on distance, the electrostatic force can be either attractive or
repulsive while the gravitational force is only repulsive, and the electrostatic force is weaker.
D. both have the same dependence on distance, the electrostatic force can be either
attractive or repulsive while the gravitational force is only attractive, and the electrostatic
force is stronger.
E. the electrostatic force falls off more rapidly with distance, the electrostatic force can be either
attractive or repulsive while gravitation is only attractive and the electrostatic force is stronger.
12. Imagine four equal positive charges, q, placed on points of a circle of radius r at the 3, 6, 9
and 12 o’clock positions. The magnitude of the electric field at the center of the circle is given
by
A. 4kq/r.
B. 4kq/r2.
C. kq/r.
D. kq/r2.
E. zero.
13. Three equal negative charges are placed at three of the four corners of a square. The
direction of the electric field at the remaining corner of the square is
A. along a side of the square toward one of the charges.
B. along a side of the square away from one of the charges.
C. along the diagonal connecting this corner and another charge, away from the other charge.
D. along the diagonal connecting this corner and another charge, toward the other charge.
E. no direction, zero field.