Question 1

A light bulb operating at a voltage of 120 V has a resistance of 200 Ω. What is the power?

Accepted Answer

A)  100 W 
B)  60 W 
C)  72 W 
D)  14 × 10-3 W 
E)  7.2 W 
A)  100 W 
B)  60 W 
C)  72 W 
D)  14 × 10-3 W 
E)  7.2 W

Question 2

FIGURE 21-19  
-Four capacitors are connected across a 90-V DC as shown in Figure 21-19. What is the voltage across the 6-μF capacitor?

Accepted Answer

A)  10 V 
B)  20 V 
C)  30 V 
D)  60 V 
E)  90 V 
A)  10 V 
B)  20 V 
C)  30 V 
D)  60 V 
E)  90 V

Question 3

A 10-A current flows for two minutes.
(a) How much charge has passed through this circuit?
(b) How many electrons have passed any point in the circuit?

Accepted Answer

(a)1200 C

Question 4

The resistivity of the material of a wire is inversely proportional to the resistance of the wire.

Accepted Answer

A) True 
 B)False

Question 5

You are given a copper bar of dimensions 3 cm × 5 cm × 8 cm and asked to attach leads to it in order to make a resistor. If you want to achieve the smallest possible resistance, you should attach the leads to the opposite faces that measure

Accepted Answer

A)  3 cm × 5 cm. 
B)  3 cm × 8 cm. 
C)  5 cm × 8 cm. 
D)  Any pair of faces produces the same resistance. 
A)  3 cm × 5 cm. 
B)  3 cm × 8 cm. 
C)  5 cm × 8 cm. 
D)  Any pair of faces produces the same resistance.

Question 6

A light bulb operating at a voltage of 120 Volt has a power of 60 W. What is the current flowing through this bulb?

Accepted Answer

A)  1.5 A 
B)  2.5 A 
C)  0.5 A 
D)  2 A 
E)  1 A 
A)  1.5 A 
B)  2.5 A 
C)  0.5 A 
D)  2 A 
E)  1 A

Question 7

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 8

A charge of 12. C passes through an electroplating apparatus in 2.0 min. What is the average current?

Accepted Answer

The answer of A charge of 12. C passes through...

Question 9

Kirchhoff's loop 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. 
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 10

A series circuit is a current divider and a parallel circuit is a voltage divider circuit.

Accepted Answer

A) True 
 B)False

Question 11

Electron flow is in the direction of conventional current.

Accepted Answer

A) True 
 B)False

Question 12

FIGURE 21-12  
-Three resistors of values 2 Ω, 6 Ω and 12 Ω are connected across a DC voltage source as shown in Figure 21-12. If the total current through the circuit is I = 5.0 A, what is the current through the 12 Ω resistor?

Accepted Answer

A)  0.5 A 
B)  0.6 A 
C)  0.7 A 
D)  0.8 A 
E)  0.9 A 
A)  0.5 A 
B)  0.6 A 
C)  0.7 A 
D)  0.8 A 
E)  0.9 A

Question 13

FIGURE 21-11  
-Four resistors of values 2 Ω, 4 Ω, 3 Ω, and 9 Ω are connected across a DC source with voltage V as shown in Figure 21-11. If the total current through this circuit is 1 A, what is the value of the voltage V?

Accepted Answer

A)  2 V 
B)  4 V 
C)  6 V 
D)  8 V 
E)  10 V 
A)  2 V 
B)  4 V 
C)  6 V 
D)  8 V 
E)  10 V

Question 14

FIGURE 21-18  
-A 5.0 μF and a 7.0 μF capacitor are connected in series across an 8.0-V DC source. What is the voltage across the 5.0 μF capacitor?

Accepted Answer

A)  0 V 
B)  8.0 V 
C)  2.7 V 
D)  3.6 V 
E)  4.7 V 
A)  0 V 
B)  8.0 V 
C)  2.7 V 
D)  3.6 V 
E)  4.7 V

Question 15

Kirchhoff's voltage rule is an example of conservation of energy.

Accepted Answer

A) True 
 B)False

Question 16

FIGURE 21-7  
-Three 2.0-Ω resistors are connected across the sides of an equilateral triangle ABC as shown in Figure 21-7. What is the equivalent resistance between any two points, AB, BC, or AC, of this circuit?

Accepted Answer

A)  2.0 Ω 
B)  6.0 Ω 
C)  4.3 Ω 
D)  3.3 Ω 
E)  1.3 Ω 
A)  2.0 Ω 
B)  6.0 Ω 
C)  4.3 Ω 
D)  3.3 Ω 
E)  1.3 Ω

Question 17

A 2.0 μF capacitor is charged to 12. V and then discharged through 4 × 106 Ω. How long will it take for the voltage across the capacitor to drop to 3.0 V?

Accepted Answer

Question 18

FIGURE 21-16  
-Four resistors of values 2 Ω, 4 Ω, 3 Ω, and 9 Ω are connected across an 8-V DC source as shown in Figure 21-16. 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 
A)  1 A 
B)  0.7 A 
C)  0.5 A 
D)  0.9 A 
E)  2 A

Question 19

FIGURE 21-13  
-A number of resistors are connected across points A and B as shown in Figure 21-13. What is the equivalent resistance between points A and B?

Accepted Answer

A)  4 Ω 
B)  6 Ω 
C)  8 Ω 
D)  10 Ω 
E)  12 Ω 
A)  4 Ω 
B)  6 Ω 
C)  8 Ω 
D)  10 Ω 
E)  12 Ω

Question 20

Describe how a simple electric cell works.

Accepted Answer

The simplest cells contain two plates or

Exam 21: Electric Current and Direct-Current Circuits

A light bulb operating at a voltage of 120 V has a resistance of 200 Ω. What is the power?

FIGURE 21-19 -Four capacitors are connected across a 90-V DC as shown in Figure 21-19. What is the voltage across the 6-μF capacitor?

A 10-A current flows for two minutes. (a) How much charge has passed through this circuit? (b) How many electrons have passed any point in the circuit?

The resistivity of the material of a wire is inversely proportional to the resistance of the wire.

You are given a copper bar of dimensions 3 cm × 5 cm × 8 cm and asked to attach leads to it in order to make a resistor. If you want to achieve the smallest possible resistance, you should attach the leads to the opposite faces that measure

A light bulb operating at a voltage of 120 Volt has a power of 60 W. What is the current flowing through this bulb?

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

A charge of 12. C passes through an electroplating apparatus in 2.0 min. What is the average current?

Kirchhoff's loop rule is a statement of

A series circuit is a current divider and a parallel circuit is a voltage divider circuit.

Electron flow is in the direction of conventional current.

FIGURE 21-12 -Three resistors of values 2 Ω, 6 Ω and 12 Ω are connected across a DC voltage source as shown in Figure 21-12. If the total current through the circuit is I = 5.0 A, what is the current through the 12 Ω resistor?

FIGURE 21-11 -Four resistors of values 2 Ω, 4 Ω, 3 Ω, and 9 Ω are connected across a DC source with voltage V as shown in Figure 21-11. If the total current through this circuit is 1 A, what is the value of the voltage V?

FIGURE 21-18 -A 5.0 μF and a 7.0 μF capacitor are connected in series across an 8.0-V DC source. What is the voltage across the 5.0 μF capacitor?

Kirchhoff's voltage rule is an example of conservation of energy.

FIGURE 21-7 -Three 2.0-Ω resistors are connected across the sides of an equilateral triangle ABC as shown in Figure 21-7. What is the equivalent resistance between any two points, AB, BC, or AC, of this circuit?

A 2.0 μF capacitor is charged to 12. V and then discharged through 4 × 106 Ω. How long will it take for the voltage across the capacitor to drop to 3.0 V?

FIGURE 21-16 -Four resistors of values 2 Ω, 4 Ω, 3 Ω, and 9 Ω are connected across an 8-V DC source as shown in Figure 21-16. What is the current through the 9-Ω resistor?

FIGURE 21-13 -A number of resistors are connected across points A and B as shown in Figure 21-13. What is the equivalent resistance between points A and B?

Describe how a simple electric cell works.

Introduction to Physics

One-Dimensional Kinematics

Vectors in Physics

Two-Dimensional Kinematics

Newtons Laws of Motion

Applications of Newtons Laws

Work and Kinetic Energy

Potential Energy and Conservation of Energy

Linear Momentum and Collisions

Rotational Kinematics and Energy

Rotational Dynamics and Static Equilibrium

Gravity

Oscillations About Equilibrium

Waves and Sound

Fluids

Temperature and Heat

Phases and Phase Changes

The Laws of Thermodynamics

Electric Charges, Forces, and Fields

Electric Potential and Electric Potential Energy

Magnetism

Magnetic Flux and Faradays Law of Induction

Alternating-Current Circuits

Electromagnetic Waves

Geometrical Optics

Optical Instruments

Physical Optics: Interference and Diffraction

Relativity

Quantum Physics

Atomic Physics

Nuclear Physics and Nuclear Radiation

Filters

A 2.0 μF capacitor is charged to 12. V and then discharged through 4 × 10⁶ Ω. How long will it take for the voltage across the capacitor to drop to 3.0 V?