Base your answers to questions 1 and 2 on the circuit diagram Base your answers to questions 3 and 4 on the circuit
it diagram
below. shown below.
1. What is the current through the 2 resistor?
A) 2 A
10
B) 33 A
C) 6 A 3. What is the potential drop from X to Y?
D) 8 A A) 1 V
E) 10 A B) 3 V
C) 6 V
2. What is the potential drop across the 4 resistor?
D) 8 V
A) 8 V
E) 12 V
B) 12 V
C) 16 V 4. What is the current through the 12resistor?
D) 18 V A) ¢ A
E) 20 V B) ¤ A
C) ½ A
D) 1 A
E) ¦ A
5. 7. Base your answer to the following question on the diagram
below which shows two resistors connected in series. A
voltage V is applied to the pair.
What is the ratio of the voltage drop over R1 to the voltage
A lamp, a voltmeter V, a ammeter A, and a battery with zero drop over R2 when R1 = 1.5R2?
internal resistance are connected as shown above. Adding
4
a second, identical lamp at point X would A) 9
2
A) increase the ammeter reading B) 3
B) decrease the ammeter reading C) 1
3
C) increase the voltmeter reading D) 2
9
D) decrease the voltmeter reading E) 4
E) produce no change in either reading
8. Kirchoff's loop rule is essentially a restatement of which of
the following?
6. Base your answer to the following question on the diagram
below which shows two resistors connected in parallel. A A) Ohm's Law
voltage V is applied to the pair.
B) Faraday's Law
C) Conservation of momentum
D) Conservation of charge
E) Conservation of energy
9. Base your answer to the following question on the circuit
shown below.
What is the ratio of the current through R1 to the current
through R2 when R1 = 1.5R2?
4
A) 9
2
B) 3
C) 1
3
D) 2 The current through the 30 resistor is most nearly
9
E) 4
A) 2 A
B) 3 A
C) 4 A
D) 6 A
E) 10 A
Base your answers to questions 10 and 11 on the diagram below Base your answers to questions 12 and 13 on the circuit diagram
which shows two different resistors, R1 and R2, in two different below which shows four resistors attached to a 10 V battery.
connections to the same source of emf that has no internal
resistance.
For each question(s) pick your answer from the following list.
I. It is greater for the parallel connection.
II. It is greater for the series connection.
III. It is the same for both connections.
IV. It is different for each connection, but one must know the
values of R1 and R2, to know which is greater.
V. It is different for each connection, but one must know the
value of to know which is greater.
12. What is the total power dissipated by this circuit?
A) 12 W
B) 24 W
C) 60 W
D) 83.3 W
10. How does the total current for these two cases compare?
E) 240 W
A) I
13. What is the ratio of the current in the 3Þ resistor to the
B) II current in the 1Þ resistor?
C) III A) 1
6
D) IV B) 1
3
E) V C) 2
3
3
D) 2
11. How does the voltage drop over R1 for these two cases
compare?
E) 3
A) I
B) II 14. A battery is manufactured with an emf of 24 volts.
However, when attached to a 2 resistor, the potential
C) III between the terminals is only 20 V, what is the internal
resistance of the battery?
D) IV
A) 0.10
E) V
B) 0.20
C) 0.30
D) 0.40
E) 0.60
Base your answers to questions 15 and 16 on the circuit diagram 18. A certain resistor has a resistance that is directly
below. proportional to its temperature. If the temperature of the
resistor is doubled, and the current through the resistor
remains constant, the voltage drop across the resistor will
A) increase by a factor of 4
B) increase by a factor of 2
C) remain the same
D) decrease by a factor of 2
E) decrease by a factor of 4
15. What is the current through the 3 Þ resistor?
A) 1 A 19. An 80 W light bulb operates at a voltage of 100 V. The
resistance of the bulb is
4
B) 3 A
A) 0.8
C) 2 A
B) 1.25
8
D) 3 A
C) 8
E) 4 A
D) 40
16. What is the power dissipated by the 4 Þ resistor? E) 125
A) 64 W
20. Three identical light bulbs are connected in parallel to a
B) 72 W voltage source. If one of the bulbs burns out
C) 96 W A) more current will be drawn from the voltage source
D) 120 W B) the light intensity of the other bulbs will decrease, but
they will not go out
E) 144 W
C) the light intensity of the other bulbs will remain the
same
17. An Ohmic conductor has it's voltage doubled while the D) the light intensity of the other bulbs will increase
resistance remains constant. The current through the
conductor will E) all the bulbs will go out
A) increase by a factor of 4
B) increase by a factor of 2
C) remain the same
D) decrease by a factor of 2
E) decrease by a factor of 4
21. 23.
In the diagram above, if the voltage drop across the 4
resistor is 24 V, find the most likely value of the unknown
resistance R.
A) 0.62
B) 3
In the diagram above, all the resistors have an identical
resistance R. If the switch S is closed, the current through
C) 4.5
the resistor R1 will
D) 9.3
A) increase and the voltage will remain the same
E) There is not enough information to find the resistance.
B) decrease and the voltage will remain the same
C) remain the same with constant voltage 24.
D) remain the same but the voltage will increase
E) remain the same but the voltage will decrease
22.
In the above circuit, find the current through the 10
resistor.
A) 0.5 A
The voltage drop across the 5 resistor in the portion of
the circuit shown above is most nearly B) 1.25 A
A) 12 V C) 1.5 A
B) 18 V D) 3 A
C) 24 V E) 5 A
D) 40 V
E) 48 V
Base your answers to questions 25 and 26 on the following circuit Base your answers to questions 27 and 28 on the circuit diagram
diagram. shown below.
25. With switch S open, the current through the 3 resistor is
27. If each of the resistors in the circuit have a resistance
A) 0.6 A of 4 , what is the equivalent resistance from point P to
point Q?
B) 0.8 A
A) 1.2
C) 2.4 A
B) 2.4
D) 4 A
C) 3.6
E) 6 A
D) 4.8
26. If the switch S is closed, the current through the 3 E) 6.0
resistor will be
A) 0.6 A 28. The total current in the circuit is 10 A, the resistors are 4
ohms each. What is the emf of the battery?
B) 0.8 A
A) 12 V
C) 2.4 A
B) 24 V
D) 4 A
C) 36 V
E) 6 A
D) 48 V
E) 60 V
29. 31. An electric circuit contains an operating heating element
and a lit lamp. Which statement best explains why the lamp
remains lit when the heating element is removed from the
circuit?
A) The lamp has less resistance than the heating element.
B) The lamp has more resistance than the heating element.
C) The lamp and the heating element were connected in
In the circuit shown above, what is the appropriate value
series.
for r so that the current through the battery is 2.5 A?
D) The lamp and the heating element were connected in
A) 1 parallel.
B) 2 E) The lamp and the heating element draw current from
separate sources.
C) 3
D) 4 32. Base your answer to the following question on the
following situation. A certain toaster draws 3 A of current
E) 6 while in household operation at 120 V.
What is the resistance of the toaster?
30. Base your answer to the following question on the part of
the circuit shown below. A) 20
B) 40
C) 60
D) 80
E) 120
If the potential difference between A and B is 4 V, how
much charge will pass though the 4 resistor in 5 seconds? 33. In order to measure the power dissipated in a resistor of
unknown value, the minimum equipment needed would be
A) 1 C A) a voltmeter only
B) 2 C B) an ammeter only
C) 4 C C) a voltmeter and an ammeter
D) 5 C D) an ammeter, a voltmeter, and a resistor of known value
E) 8 C E) a voltmeter and a magnet producing a known magnetic
field
34. Several circuit components are placed in series in a circuit
and connected to a voltage source. Across which
component is the potential difference greatest?
A) The one with the least resistance.
B) The one with the greatest resistance.
C) The one whose resistance is nearest to the average
resistance of the components.
D) The potential difference is the same across each
component.
E) There is no potential difference across components
because there is a voltage source connected.
Answer Key
Equivalent Resistors MC Questions [Mar 28, 2011]
1. C 31. D
2. A 32. B
3. C 33. C
4. C 34. B
5. B
6. B
7. D
8. E
9. C
10. A
11. A
12. D
13. C
14. D
15. D
16. A
17. B
18. B
19. E
20. C
21. C
22. B
23. D
24. D
25. C
26. D
27. B
28. B
29. C
30. D
Name ________________________________ Class __________________________ Date ___________
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