Extra review (electricity and magnetism) by shykh salam
1. Physics 11 Course Review – Sample questions and additional practice
Unit 3 – Electricity and Magnetism
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 1. A positive charge attracts object X. A negative charge repels object Y. Object X is attracted to object Y.
Which is of the following is the most likely explanation?
a. Object X has a positive charge. Object Y has a negative charge.
b. Object X has a negative charge. Object Y has a negative charge.
c. Object X has a positive charge. Object Y has a positive charge.
d. Object X has a negative charge. Object Y has a positive charge.
e. Object X has a neutral charge. Object Y has a negative charge.
____ 2. A sweater will end up with a negative charge when it
a. loses electrons d. gains protons
b. loses protons e. loses neutrons
c. gains electrons
____ 3. The leaves of a negatively charged electroscope spread apart even more when a charged rod is brought
near. The charge on the rod must be
a. negative d. either positive or negative
b. positive e. very large
c. neutral
____ 4. An uncharged pith ball is
a. attracted by another uncharged pith ball
b. attracted by a negatively charged pith ball
c. attracted by a positively charged pith ball
d. both A and B
e. both B and C
____ 5. How many types of electrostatic charges have been discovered?
a. 1 d. 4
b. 2 e. 5
c. 3
____ 6. The electrons in a metal sphere can be made to move by placing a charged object near it. This process is
called
a. friction d. contact
b. induction e. induction and grounding
c. grounding
____ 7. To give an electrically neutral object a positive charge, you must
a. add electrons to it
b. remove electrons from it
c. add protons to it
d. remove protons from it
e. remove neutrons from it
____ 8. Which particles in an atom have an electrical charge?
a. proton and neutron d. neutron and nucleus
b. electron and proton e. all of the above
c. neutron and electron
____ 9. A negatively charged rod is held near a neutral pith ball. Before the objects touch, they will _____ one
another. After they touch, they will _____ one another.
a. attract, repel
b. attract, attract
c. repel, repel
d. repel, attract
e. attract, not affect
2. ____ 10. Two touching metal spheres, X and Y, are placed on insulated stands. A negatively charged rod is
brought close to sphere X. Sphere Y is then removed. As a result,
a. Both spheres will have a negative charge.
b. Both spheres will have a positive charge.
c. Both spheres will have neutral charges.
d. Sphere X will have a negative charge. Sphere Y will have a positive charge.
e. Sphere X will have a positive charge. Sphere Y will have a negative charge.
____ 11. The Earth is a good ground because
a. It has a large mass.
b. It has a large charge.
c. It can absorb or give up extra electrons easily.
d. It attracts negative charges.
e. It attracts positive charges.
____ 12. Which part of an atom has the greatest mass?
a. electron d. nucleus
b. proton e. ion
c. neutron
____ 13. How many electrons must be transferred to a neutral pith ball to give it a charge of –8.0 × 10–16
C?
a. 8.0 × 1016
d. 8.0 × 103
b. 5.0 × 10 2
e. 2.0 × 10 4
c. 5.0 × 10 3
____ 14. If 15 C passes a point in a circuit in 5.0 s, the current in the circuit is
a. 75 A d. 15 A
b. 3.0 A e. 5.0 A
c. 0.33 A
____ 15. A circuit has a current of 345 mA. How much charge passes a point in the circuit in 2.00 min?
a. 0.690 A d. 20.7 A
b. 2.88 A e. 41.4 A
c. 5.75 A
____ 16. How many seconds will it take for 10.0 C of charge to pass through a 12.0 A circuit?
a. 120 s d. 100 s
b. 0.120 s e. 1.20 s
c. 0.833 s
____ 17. In circuits, the term electron flow refers to
a. the direction of electron movement d. the number of electrons
b. the direction of the electric current e. the total charge of the electrons
c. the rate of electron movement
____ 18. The SI unit for measuring potential difference is the
a. coulomb d. joule
b. ampere e. watt
c. volt
____ 19. What is the potential difference of a battery if it provides 250 J of energy to a load in a 12.0 A circuit in
2.3 s?
a. 9.1 V d. 1.35 × 103
V
b. 6.9 × 103
V e. 28 V
c. 48 V
____ 20. A hair dryer operates from a 120-V source. If it has consumed 840 J of energy, what total charge has
passed through it?
a. 1.0 × 105
C d. 7.0 C
b. 1.0 × 102
C e. 0.14 C
c. 71 C
3. ____ 21. An electron has a mass of 9.11 × 10–31
kg. Originally, it is at rest. What speed will the electron have after
it is accelerated though a potential difference of 5.67 × 103
V?
a. 5.67 × 103
m/s d. 3.16 × 107
m/s
b. 1.99 × 10 15
m/s e. 3.00 × 108
m/s
c. 4.46 ×107
m/s
____ 22. Which device would most likely be classified as a load in an electrical circuit?
a. battery d. cell
b. light bulb e. none of the above
c. ammeter
____ 23. Kirchoff's law of voltages states that in a complete circuit,
a. The sum of voltage decreases equals the sum of voltage increases.
b. All paths in a circuit have equal voltage increases.
c. All electrons must travel the same path.
d. Electrons provide the necessary voltage for the circuit to operate.
e. The voltage is equal to the energy divided by the current.
____ 24. If ten 9.0-V sources are connected in series, the total potential difference in the circuit will be
a. 0.90 V d. 90 V
b. 1.1 V e. 900 V
c. 9.0 V
____ 25. If ten 9.0-V sources are connected in parallel to each other, the total potential difference in the circuit
will be
a. 0.90 V d. 90 V
b. 1.1 V e. 900 V
c. 9.0 V
____ 26. The value of V2 in the following circuit is
a. 40 V d. 15 V
b. 35 V e. 10 V
c. 25 V
____ 27. The value of V2 in the following circuit is
a. 40 V d. 15 V
b. 30 V e. 10 V
c. 20 V
4. ____ 28. The value of I3 in the following circuit is
a. 10 A d. 2.0 A
b. 1.0 A e. 20 A
c. 2.5 A
____ 29. The units used to measure charge, current, potential difference, and resistance are, respectively,
a. ampere, joule, ohm, volt d. ampere, joule, volt, ohm
b. coulomb, ampere, volt, ohm e. ampere, coulomb, ohm, volt
c. coulomb, ampere, ohm, watt
____ 30. A 30.0-Ω resistor is connected in series to a 10.0-Ω resistor, and a 120-V supply. The current through the
30.0-Ω resistor will be
a. 3.0 A d. 15 A
b. 4.0 A e. 0.33 A
c. 12 A
____ 31. The electrons travelling through a circuit may be compared to red blood cells moving through the
circulatory system. Which of the following best corresponds to the load in a circuit?
a. red blood cells d. lungs
b. veins and arteries e. muscles and other tissues of the body
c. oxygen
____ 32. A toy train set has a resistance of 20.0 Ω and uses a current of 250 mA. If it ran for
one hour, what is the power of the train?
a. 1.2 W d. 2.2 × 102
W
b. 5.0 W e. 4.5 × 103
W
c. 75 W
____ 33. A fuse is rated at 15.0 A. If it is part of a 120-V circuit, which of the following could be connected
without blowing the fuse?
a. 200-W mixer d. any of the above, individually
b. 800-W toaster e. none of the above
c. 1000-W hair dryer
____ 34. Three 10.0-Ω resistors are connected in parallel to one another in a 12.0-A circuit. The total resistance in
the circuit is
a. 0.0333 Ω d. 20.0 Ω
b. 0.300 Ω e. 30.0 Ω
c. 3.33 Ω
____ 35. Which statement about the magnetic north pole of Earth is true?
a. Its location never changes.
b. It corresponds to the N-pole of a bar magnet.
c. It corresponds to the S-pole of a bar magnet.
d. It is at the same location as the geographic north pole of Earth.
e. both B and D
____ 36. An iron nail can be turned into a temporary magnet if it is held in a strong magnetic field. This method of
magnetization is called
a. induction d. charging
b. saturation e. convection
c. conduction
5. ____ 37. The following diagram shows the current direction in a straight conductor. The magnetic field lines
around the conductor should be drawn as
a. concentric clockwise circles around the conductor
b. concentric counterclockwise circles around the conductor
c. straight lines in the same direction as the current
d. straight lines in the opposite direction to the current
e. straight lines radiating out from the conductor
____ 38. The magnetic field lines inside a coil
a. are straight d. all of the above
b. point in the same direction e. none of the above
c. are equally spaced
____ 39. The brushes of a DC motor
a. connect the coil to the armature
b. provide a permanent magnetic field
c. allow the armature to spin easily
d. connect the coil to the circuit
e. change direction with every rotation of the armature
____ 40. If the split-ring commutator of a DC motor was replaced with a solid commutator ring, the armature
would
a. rotate more quickly
b. rotate in the opposite direction
c. stop when the coil was at right angles to the magnetic field
d. stop when the coil was parallel to the magnetic field
e. rotate more slowly
____ 41. When a bar magnet is inserted into a coil, a current of 12.0 A is induced in the coil. If four magnets of
the same type are inserted into the coil at the same time, the induced current would be
a. 3.00 A d. 48.0 A
b. 4.00 A e. 60.0 A
c. 12.0 A
____ 42. Which of the following factors does not affect the size of the induced current in a coil?
a. number of turns in the coil d. size of the inducing field
b. rate of change of the inducing field e. direction of the windings in the coil
c. resistance of the wire in the coil
____ 43. To use the right hand rule to predict the direction of an induced current in a coil, your thumb must point
a. To the N-pole of the induced magnetic field.
b. To the S-pole of the induced magnetic field.
c. In the direction of the induced current.
d. In the direction of the inducing field.
e. In the direction of the electron flow.
____ 44. The diagram below shows a bar magnet being moved away from a coil. The pole induced at the side
closest to the magnet will be a(n) ____-pole and the current will flow ____ at the front of the coil.
a. N, up d. N, down
b. N, down e. positive, down
c. S, up
____ 45. The advantage of AC power over DC power is that
a. AC power allows the operation of transformers.
b. AC power travels though wires with less energy loss.
6. c. AC power can be transmitted at higher voltages.
7. Physics Review
Electricity and Magnetism Answer Section
MULTIPLE CHOICE
1. ANS: E
2. ANS: C
3. ANS: A
4. ANS: E
5. ANS: B
6. ANS: B
7. ANS: B
8. ANS: B
9. ANS: A
10. ANS: E
11. ANS: C
12. ANS: D
13. ANS: C
14. ANS: B
15. ANS: E
16. ANS: C
17. ANS: A
18. ANS: C
19. ANS: A
20. ANS: D
21. ANS: C
22. ANS: B
23. ANS: A
24. ANS: D
25. ANS: C
26. ANS: C
27. ANS: B
28. ANS: A
29. ANS: B
30. ANS: A
31. ANS: E
32. ANS: A
33. ANS: D
34. ANS: C
35. ANS: C
36. ANS: A
37. ANS: B
38. ANS: D
39. ANS: D
40. ANS: C
41. ANS: D
42. ANS: E
43. ANS: A
44. ANS: C
45. ANS: A