Question 1

FIGURE 26-8 2 + R3I3 + E3 - R2I2 = 0 B) E2 + R3I3 - E3 + R2I2 = 0 C) E2 - R3I3 - E3 - R2I2 = 0 D) E2 + R3I3 + E3 + R2I2 = 0 E) -E2 + R3I3 - E3 + R2I2 = 0" class="answers-bank-image d-inline" rel="preload" >
-For the circuit shown in Fig. 26-8, which equation is correct for loop2 (going clockwise) ?

Accepted Answer

A)  E2 + R3I3 + E3 - R2I2 = 0
B)  E2 + R3I3 - E3 + R2I2 = 0
C)  E2 - R3I3 - E3 - R2I2 = 0
D)  E2 + R3I3 + E3 + R2I2 = 0
E)  -E2 + R3I3 - E3 + R2I2 = 0 B

Question 2

A small galvanometer coil of resistance R = 20 Ω and full-scale deflection at 1 mA is connected in series with a 4980 Ω resistance to build an analog voltmeter. What is the maximum voltage that this voltmeter can read?

Accepted Answer

A)  3 V
B)  1 V
C)  50 V
D)  5 V
E)  10 V D

Question 3

FIGURE 26-24 
-Four resistors of values 2 Ω, 4 Ω, 3 Ω, and 9 Ω are connected across an 8-V DC source as shown in Fig. 26-24. What is the current through the 9-Ω resistor?

Accepted Answer

A)  1 A
B)  0.7 A
C)  0.5 A
D)  0.9 A
E)  2 A

Question 4

Four equal resistors connected across a DC voltage source in either series or parallel will have equal voltage drops across each resistor.

Accepted Answer

A) True 
 B)False

Question 5

FIGURE 26-1 
-Fig. 26-1 shows three identical lightbulbs connected to a battery. What happens to the brightness of lightbulb 1 when the switch S is closed?

Accepted Answer

A)  The brightness will increase momentarily then return to its previous level.
B)  The brightness increases.
C)  The brightness will decrease momentarily then return to its previous level.
D)  The brightness remains the same as before the switch is closed.
E)  The brightness decreases.

Question 6

A 4.0-μF capacitor is charged to 6.0-V. It is then connected in series with a 3.0-MΩ resistor and connected to a 12-V battery. How long after being connected to the battery will the voltage across the capacitor be 9.0 V?

Accepted Answer

A)  5.5 s
B)  7.2 s
C)  8.3 s
D)  12 s
E)  17 s C

Question 7

An analog ammeter able to have a 0.5 A maximum reading is to be built using a small coil of resistance R = 20 Ω, and full scale deflection at 1 mA. What resistance should be added to this coil and how should it be connected to the coil?

Accepted Answer

A)  0.08 Ω in parallel
B)  0.5 Ω in parallel
C)  0.02 Ω in series
D)  20.4 Ω in parallel
E)  0.04 Ω in parallel

Question 8

You obtain a 100-W light bulb and a 50-W light bulb. Instead of connecting them in the normal way, you devise a circuit that places them in series across normal household voltage. Which statement is correct?

Accepted Answer

A)  Both bulbs glow at the same reduced brightness.
B)  Both bulbs glow at the same increased brightness.
C)  The 100-W bulb glows more brightly than the 50-W bulb.
D)  The 50-W bulb glows more brightly than the 100-W bulb.

Question 9

FIGURE 26-16 
-A 100 V DC signal is applied to four resistors as shown in Fig. 26-16. The values of the resistors are 20 Ω, 40 Ω, 60 Ω, and 80 Ω. What is the voltage across the 40 Ω resistor?

Accepted Answer

A)  20 V
B)  40 V
C)  60 V
D)  80 V
E)  100 V

Question 10

As more resistors are added in series to a constant voltage source, the power supplied by the source

Accepted Answer

A)  increases.
B)  decreases.
C)  does not change.
D)  increases for a time and then starts to decrease.
E)  decreases for a time and then starts to increase.

Question 11

Kirchhoff's junction rule is a statement of

Accepted Answer

A)  the law of conservation of momentum.
B)  the law of conservation of charge.
C)  the law of conservation of energy.
D)  the law of conservation of angular momentum.
E)  Newton's second law.

Question 12

An ideal voltmeter is one that does not change the behavior of a circuit when it is properly used to measure potential difference. The internal resistance of such a meter is

Accepted Answer

A)  dependent on the circuit.
B)  infinite.
C)  the same resistance as the circuit.
D)  0 Ω.
E)  cannot be determined

Question 13

An RC circuit is connected across a DC voltage source through an open switch. As soon as the switch is closed, the capacitor charges linearly as a function of time.

Accepted Answer

A) True 
 B)False

Question 14

In order to construct a voltmeter from a galvanometer, one normally would

Accepted Answer

A)  use a very small shunt resistor.
B)  use a very large shunt resistor.
C)  use a very small series resistor.
D)  use a very large series resistor.

Question 15

The electromotive force of a battery is the maximum potential difference between the terminals of the battery.

Accepted Answer

A) True 
 B)False

Question 16

FIGURE 26-29 
-In Fig. 26-29, I = 0.5 A and R = 12 Ω. What is the value of the emf E?

Accepted Answer

A)  18 V
B)  24 V
C)  6 V
D)  12 V
E)  48 V

Question 17

Four unequal resistors are connected in a series circuit. Which one of the following statements is correct about this circuit?

Accepted Answer

A)  The total resistance is equal to any one of the resistors.
B)  The total resistance is equal to average of the four resistors.
C)  The total resistance is less than the smallest resistor.
D)  The total resistance is less than the largest resistor.
E)  The total resistance is more than the largest resistor.

Question 18

A 6-Ω resistor, an 8-Ω resistor, and a 24-Ω resistor are connected together. What is the minimum resistance that can be produced using all three resistors?

Accepted Answer

A)  4 Ω
B)  (1/24)  Ω
C)  3 Ω
D)  (1/6)  Ω
E)  7 Ω

Question 19

A 2.0-μF capacitor is charged to 12 V and then discharged through a 4.0 × 106 Ω resistor. How long will it take for the voltage across the capacitor to drop to 3.0 V?

Accepted Answer

A)  4.5 s
B)  8.0 s
C)  11 s
D)  22 s
E)  24 s

Question 20

The potential difference between the terminals of a battery, when current flows to an external circuit, is referred to as the

Accepted Answer

A)  emf.
B)  terminal voltage.

Exam 26: Dc Circuits

FIGURE 26-8 -For the circuit shown in Fig. 26-8, which equation is correct for loop2 (going clockwise) ?

Correct AnswerverifiedB

A small galvanometer coil of resistance R = 20 Ω and full-scale deflection at 1 mA is connected in series with a 4980 Ω resistance to build an analog voltmeter. What is the maximum voltage that this voltmeter can read?

Correct AnswerverifiedD

FIGURE 26-24 -Four resistors of values 2 Ω, 4 Ω, 3 Ω, and 9 Ω are connected across an 8-V DC source as shown in Fig. 26-24. What is the current through the 9-Ω resistor?

Correct AnswerverifiedShow Answer

Four equal resistors connected across a DC voltage source in either series or parallel will have equal voltage drops across each resistor.

Correct AnswerverifiedShow Answer

FIGURE 26-1 -Fig. 26-1 shows three identical lightbulbs connected to a battery. What happens to the brightness of lightbulb 1 when the switch S is closed?

Correct AnswerverifiedShow Answer

A 4.0-μF capacitor is charged to 6.0-V. It is then connected in series with a 3.0-MΩ resistor and connected to a 12-V battery. How long after being connected to the battery will the voltage across the capacitor be 9.0 V?

Correct AnswerverifiedC

An analog ammeter able to have a 0.5 A maximum reading is to be built using a small coil of resistance R = 20 Ω, and full scale deflection at 1 mA. What resistance should be added to this coil and how should it be connected to the coil?

Correct AnswerverifiedShow Answer

You obtain a 100-W light bulb and a 50-W light bulb. Instead of connecting them in the normal way, you devise a circuit that places them in series across normal household voltage. Which statement is correct?

Correct AnswerverifiedShow Answer

FIGURE 26-16 -A 100 V DC signal is applied to four resistors as shown in Fig. 26-16. The values of the resistors are 20 Ω, 40 Ω, 60 Ω, and 80 Ω. What is the voltage across the 40 Ω resistor?

Correct AnswerverifiedShow Answer

As more resistors are added in series to a constant voltage source, the power supplied by the source

Correct AnswerverifiedShow Answer

Kirchhoff's junction rule is a statement of

Correct AnswerverifiedShow Answer

An ideal voltmeter is one that does not change the behavior of a circuit when it is properly used to measure potential difference. The internal resistance of such a meter is

Correct AnswerverifiedShow Answer

An RC circuit is connected across a DC voltage source through an open switch. As soon as the switch is closed, the capacitor charges linearly as a function of time.

Correct AnswerverifiedShow Answer

In order to construct a voltmeter from a galvanometer, one normally would

Correct AnswerverifiedShow Answer

The electromotive force of a battery is the maximum potential difference between the terminals of the battery.

Correct AnswerverifiedShow Answer

FIGURE 26-29 -In Fig. 26-29, I = 0.5 A and R = 12 Ω. What is the value of the emf E?

Correct AnswerverifiedShow Answer

Four unequal resistors are connected in a series circuit. Which one of the following statements is correct about this circuit?

Correct AnswerverifiedShow Answer

A 6-Ω resistor, an 8-Ω resistor, and a 24-Ω resistor are connected together. What is the minimum resistance that can be produced using all three resistors?

Correct AnswerverifiedShow Answer

A 2.0-μF capacitor is charged to 12 V and then discharged through a 4.0 × 106 Ω resistor. How long will it take for the voltage across the capacitor to drop to 3.0 V?

Correct AnswerverifiedShow Answer

The potential difference between the terminals of a battery, when current flows to an external circuit, is referred to as the

Correct AnswerverifiedShow Answer

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B

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C

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A 2.0-μF capacitor is charged to 12 V and then discharged through a 4.0 × 10⁶ Ω resistor. How long will it take for the voltage across the capacitor to drop to 3.0 V?

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