Question 1

A multiloop circuit is shown in the figure. Some circuit quantities are not labeled. It is not necessary to solve the entire circuit. The emf ε is closest to

Accepted Answer

A)  +3 V. 
B)  +19 V. 
C)  -3 V. 
D)  -10 V. 
E)  -1 V. 
A)  +3 V. 
B)  +19 V. 
C)  -3 V. 
D)  -10 V. 
E)  -1 V.

Question 2

The heater element of a particular 120-V toaster is a 8.9-m length of nichrome wire, whose diameter is 0.86 mm. The resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6 Ω ∙ m. If the toaster is operated at a voltage of 120 V, how much power does it draw?

Accepted Answer

A)  720 W 
B)  700 W 
C)  750 W 
D)  770 W 
E)  800 W 
A)  720 W 
B)  700 W 
C)  750 W 
D)  770 W 
E)  800 W

Question 3

A light bulb is connected in the circuit shown in the figure with the switch S open. All the connecting leads have no appreciable resistance and the battery has no internal resistance. When we close the switch, which statements below accurately describe the behavior of the circuit? (There may be more than one correct choice.)

Accepted Answer

A)  The brightness of the bulb will increase. 
B)  The brightness of the bulb will decrease. 
C)  The brightness of the bulb will not change. 
D)  The potential drop across R2 will decrease. 
E)  The potential drop across R2 will not change. 
A)  The brightness of the bulb will increase. 
B)  The brightness of the bulb will decrease. 
C)  The brightness of the bulb will not change. 
D)  The potential drop across R2 will decrease. 
E)  The potential drop across R2 will not change.

Question 4

For the circuit shown in the figure, determine the current in
(a) the 7.0-Ω resistor.
(b) the 8.0-Ω resistor.
(c) the 4.0-Ω resistor.

Accepted Answer

(a) 1.6 A

Question 5

For the circuit shown in the figure, what is the current through resistor R3?

Accepted Answer

A)  0.043 A 
B)  1.5 A 
C)  0.028 A 
D)  0.086 A 
A)  0.043 A 
B)  1.5 A 
C)  0.028 A 
D)  0.086 A

Question 6

A 6.0-μF capacitor is connected in series with a 5.0 MΩ resistor, and this combination is connected across an ideal 15-V DC battery. What is the current in the circuit when the capacitor has reached 20% of its maximum charge?

Accepted Answer

A)  6.5 μA 
B)  2.4 μA 
C)  1.3 μA 
D)  4.7 μA 
E)  9.1 μA 
A)  6.5 μA 
B)  2.4 μA 
C)  1.3 μA 
D)  4.7 μA 
E)  9.1 μA

Question 7

For the circuit shown in the figure, what is the current through resistor R1?

Accepted Answer

A)  0.071 A 
B)  0.13 A 
C)  0.029 A 
D)  0.016 A 
A)  0.071 A 
B)  0.13 A 
C)  0.029 A 
D)  0.016 A

Question 8

In the figure, when the terminal voltage Vab of the battery is equal to 20 V, how much current passes through the battery, including its direction?

Accepted Answer

A)  4 A, from a to b 
B)  5 A, from a to b 
C)  6 A, from a to b 
D)  4 A, from b to a 
E)  5 A, from b to a 
A)  4 A, from a to b 
B)  5 A, from a to b 
C)  6 A, from a to b 
D)  4 A, from b to a 
E)  5 A, from b to a

Question 9

The emf and the internal resistance of a battery are shown in the figure. If a current of 7.8 A is established through the battery from b to a, what is the terminal voltage Vab of the battery?

Accepted Answer

A)  -30 V 
B)  80 V 
C)  30 V 
D)  -80 V 
E)  zero 
A)  -30 V 
B)  80 V 
C)  30 V 
D)  -80 V 
E)  zero

Question 10

The resistivity of gold is 2.44 × 10-8 Ω ∙ m at room temperature. A gold wire that is 1.8 mm in diameter and 11 cm long carries a current of 170 mA. How much power is dissipated in the wire?

Accepted Answer

A)  0.030 mW 
B)  0.0076 mW 
C)  0.013 mW 
D)  0.019 mW 
E)  0.025 mW 
A)  0.030 mW 
B)  0.0076 mW 
C)  0.013 mW 
D)  0.019 mW 
E)  0.025 mW

Question 11

Two unknown resistors are connected together. When they are connected in series their equivalent resistance is 15 Ω. When they are connected in parallel, their equivalent resistance is 3.3 Ω. What are the resistances of these resistors?

Accepted Answer

The answer of Two unknown resistors are connected together. When...

Question 12

The voltage and power ratings of a particular light bulb, which are its normal operating values, are 110 V and 60 W. Assume the resistance of the filament of the bulb is constant and is independent of operating conditions. If the light bulb is operated with a current that is 50% of the current rating of the bulb, what is the actual power drawn by the bulb?

Accepted Answer

A)  10 W 
B)  15 W 
C)  20 W 
D)  25 W 
E)  30 W 
A)  10 W 
B)  15 W 
C)  20 W 
D)  25 W 
E)  30 W

Question 13

In the circuit shown in the figure, four identical resistors labeled A to D are connected to a battery as shown. S1 and S2 are switches. Which of the following actions would result in the GREATEST amount of current through resistor A?

Accepted Answer

A)  closing both switches 
B)  closing S1 only 
C)  closing S2 only 
D)  leaving both switches open as shown. 
A)  closing both switches 
B)  closing S1 only 
C)  closing S2 only 
D)  leaving both switches open as shown.

Question 14

A resistor is made out of a long wire having a length L. Each end of the wire is attached to a terminal of a battery providing a constant voltage V0. A current I flows through the wire. If the wire were cut in half, making two wires of length L/2, and both wires were attached to the battery (the end of both wires attached to one terminal, and the other ends attached to the other terminal), what would be the total current flowing through the two wires?

Accepted Answer

A)  4I 
B)  2I 
C)  I 
D)  I/2 
E)  I/4 
A)  4I 
B)  2I 
C)  I 
D)  I/2 
E)  I/4

Question 15

For the circuit shown in the figure, what current does the ideal ammeter read?

Accepted Answer

A)  0.033 A 
B)  0.078 A 
C)  0.23 A 
D)  0.12 A 
A)  0.033 A 
B)  0.078 A 
C)  0.23 A 
D)  0.12 A

Question 16

A galvanometer with a resistance of 40.0 Ω deflects full scale at a current of 2.0 mA. What resistance should be used with this galvanometer in order to construct a voltmeter that can read a maximum of 50 V?

Accepted Answer

A)  25 kΩ 
B)  27 kΩ 
C)  29 kΩ 
D)  31 kΩ 
E)  35 kΩ 
A)  25 kΩ 
B)  27 kΩ 
C)  29 kΩ 
D)  31 kΩ 
E)  35 kΩ

Question 17

Three resistors having resistances of 4.0 Ω, 6.0 Ω, and 10.0 Ω are connected in parallel. If the combination is connected in series with an ideal 12-V battery and a 2.0-Ω resistor, what is the current through the 10.0-Ω resistor?

Accepted Answer

A)  0.59 A 
B)  2.7 A 
C)  6.4 A 
D)  11.2 A 
E)  16 A 
A)  0.59 A 
B)  2.7 A 
C)  6.4 A 
D)  11.2 A 
E)  16 A

Question 18

Two light bulbs, B1 and B2, are connected to a battery having appreciable internal resistance as shown in the figure. What happens to the brightness of bulb B1 when we close the switch S?

Accepted Answer

A)  The brightness of B1 increases permanently. 
B)  The brightness of B1 decreases permanently. 
C)  The brightness of B1 does not change. 
D)  The brightness of B1 increases temporarily but gradually decreases back to its original brightness. 
E)  The brightness of B1 decreases temporarily but gradually increases back to its original brightness. 
A)  The brightness of B1 increases permanently. 
B)  The brightness of B1 decreases permanently. 
C)  The brightness of B1 does not change. 
D)  The brightness of B1 increases temporarily but gradually decreases back to its original brightness. 
E)  The brightness of B1 decreases temporarily but gradually increases back to its original brightness.

Question 19

A galvanometer has an internal resistance of 100 Ω and deflects full-scale at a current of 2.00 mA. What size resistor should be added to it to convert it to a millivoltmeter capable of reading up to 400 mV, and how should this resistor be connected to the galvanometer?

Accepted Answer

A)  50.0 Ω in series with the galvanometer 
B)  50.0 Ω in parallel with the galvanometer 
C)  75.0 Ω in parallel with the galvanometer 
D)  100 Ω in series with the galvanometer 
E)  100 Ω in parallel with the galvanometer 
A)  50.0 Ω in series with the galvanometer 
B)  50.0 Ω in parallel with the galvanometer 
C)  75.0 Ω in parallel with the galvanometer 
D)  100 Ω in series with the galvanometer 
E)  100 Ω in parallel with the galvanometer

Question 20

A 400-W computer (including the monitor) is turned on for 8.0 hours per day. If electricity costs 10¢ per kWh, how much does it cost to run the computer annually for a typical 365-day year?

Accepted Answer

A)  $120 
B)  $1200 
C)  $15 
D)  $17 
E)  $150 
A)  $120 
B)  $1200 
C)  $15 
D)  $17 
E)  $150

Exam 28: Fundamentals of Circuits

A multiloop circuit is shown in the figure. Some circuit quantities are not labeled. It is not necessary to solve the entire circuit. The emf ε is closest to

The heater element of a particular 120-V toaster is a 8.9-m length of nichrome wire, whose diameter is 0.86 mm. The resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6 Ω ∙ m. If the toaster is operated at a voltage of 120 V, how much power does it draw?

For the circuit shown in the figure, determine the current in (a) the 7.0-Ω resistor. (b) the 8.0-Ω resistor. (c) the 4.0-Ω resistor.

For the circuit shown in the figure, what is the current through resistor R3?

A 6.0-μF capacitor is connected in series with a 5.0 MΩ resistor, and this combination is connected across an ideal 15-V DC battery. What is the current in the circuit when the capacitor has reached 20% of its maximum charge?

For the circuit shown in the figure, what is the current through resistor R1?

In the figure, when the terminal voltage Vab of the battery is equal to 20 V, how much current passes through the battery, including its direction?

The emf and the internal resistance of a battery are shown in the figure. If a current of 7.8 A is established through the battery from b to a, what is the terminal voltage Vab of the battery?

The resistivity of gold is 2.44 × 10-8 Ω ∙ m at room temperature. A gold wire that is 1.8 mm in diameter and 11 cm long carries a current of 170 mA. How much power is dissipated in the wire?

Two unknown resistors are connected together. When they are connected in series their equivalent resistance is 15 Ω. When they are connected in parallel, their equivalent resistance is 3.3 Ω. What are the resistances of these resistors?

In the circuit shown in the figure, four identical resistors labeled A to D are connected to a battery as shown. S1 and S2 are switches. Which of the following actions would result in the GREATEST amount of current through resistor A?

For the circuit shown in the figure, what current does the ideal ammeter read?

A galvanometer with a resistance of 40.0 Ω deflects full scale at a current of 2.0 mA. What resistance should be used with this galvanometer in order to construct a voltmeter that can read a maximum of 50 V?

Three resistors having resistances of 4.0 Ω, 6.0 Ω, and 10.0 Ω are connected in parallel. If the combination is connected in series with an ideal 12-V battery and a 2.0-Ω resistor, what is the current through the 10.0-Ω resistor?

Two light bulbs, B1 and B2, are connected to a battery having appreciable internal resistance as shown in the figure. What happens to the brightness of bulb B1 when we close the switch S?

A galvanometer has an internal resistance of 100 Ω and deflects full-scale at a current of 2.00 mA. What size resistor should be added to it to convert it to a millivoltmeter capable of reading up to 400 mV, and how should this resistor be connected to the galvanometer?

A 400-W computer (including the monitor) is turned on for 8.0 hours per day. If electricity costs 10¢ per kWh, how much does it cost to run the computer annually for a typical 365-day year?

Concepts of Motion

Kinematics in One Dimension

Vectors and Coordinate Systems

Kinematics in Two Dimensions

Force and Motion

Dynamics I: Motion Along a Line

Newtons Third Law

Dynamics Ii: Motion in a Plane

Work and Kinetic Energy

Interactions and Potential Energy

Impulse and Momentum

Rotation of a Rigid Body

Newtons Theory of Gravity

Fluids and Elasticity

Oscillations

Traveling Waves

Superposition

A Macroscopic Description of Matter

Work, Heat, and the First Law of Thermodynamics

The Micromacro Connection

Heat Engines and Refrigerators

Electric Charges and Forces

The Electric Field

Gausss Law

The Electric Potential

Potential and Field

Current and Resistance

The Magnetic Field

Electromagnetic Induction

Electromagnetic Fields and Waves

Ac Circuits

Wave Optics

Ray Optics

Optical Instruments

Relativity

The Foundations of Modern Physics

Quantization

Wave Functions and Uncertainty

One-Dimensional Quantum Mechanics

Atomic Physics

Nuclear Physics

Filters

The heater element of a particular 120-V toaster is a 8.9-m length of nichrome wire, whose diameter is 0.86 mm. The resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10^-6 Ω ∙ m. If the toaster is operated at a voltage of 120 V, how much power does it draw?

For the circuit shown in the figure, what is the current through resistor R₃?

For the circuit shown in the figure, what is the current through resistor R₁?

In the figure, when the terminal voltage V_ab of the battery is equal to 20 V, how much current passes through the battery, including its direction?

The emf and the internal resistance of a battery are shown in the figure. If a current of 7.8 A is established through the battery from b to a, what is the terminal voltage V_ab of the battery?

The resistivity of gold is 2.44 × 10^-8 Ω ∙ m at room temperature. A gold wire that is 1.8 mm in diameter and 11 cm long carries a current of 170 mA. How much power is dissipated in the wire?

In the circuit shown in the figure, four identical resistors labeled A to D are connected to a battery as shown. S₁ and S₂ are switches. Which of the following actions would result in the GREATEST amount of current through resistor A?

Two light bulbs, B₁ and B₂, are connected to a battery having appreciable internal resistance as shown in the figure. What happens to the brightness of bulb B₁ when we close the switch S?