Question 1

If R = 2.0 kΩ, C = 4.0 mF, ε = 8.0 V, Q = 20 mC, and I = 3.0 mA, what is the potential difference Vb − Va?

Accepted Answer

A) +7.0 V 
B) +19 V 
C) +9.0 V 
D) −3.0 V 
E) −14 V 
A) +7.0 V 
B) +19 V 
C) +9.0 V 
D) −3.0 V 
E) −14 V

Question 2

The battery is disconnected from a series RC circuit after the capacitor is fully charged and is replaced by an open switch. When the switch is closed,

Accepted Answer

A) the current through the resistor is always greater than the current through the capacitor. 
B) the current through the resistor is always less than the current through the capacitor. 
C) the current through the resistor is always equal to the current through the capacitor. 
D) the capacitor does not allow current to pass. 
E) the current stops in the resistor. 
A) the current through the resistor is always greater than the current through the capacitor. 
B) the current through the resistor is always less than the current through the capacitor. 
C) the current through the resistor is always equal to the current through the capacitor. 
D) the capacitor does not allow current to pass. 
E) the current stops in the resistor.

Question 3

The circuit below contains three 100-W light bulbs and a capacitor. The emf is 110 V and the capacitor is fully charged. Which light bulb(s) is(are) brightest?

Accepted Answer

A) A 
B) B 
C) C 
D) A and B 
E) A and C 
A) A 
B) B 
C) C 
D) A and B 
E) A and C

Question 4

What is the magnitude of the potential difference across the 20-Ω resistor?

Accepted Answer

A) 3.2 V 
B) 7.8 V 
C) 11 V 
D) 5.0 V 
E) 8.6 V 
A) 3.2 V 
B) 7.8 V 
C) 11 V 
D) 5.0 V 
E) 8.6 V

Question 5

A battery has an internal resistance of 4.0 Ω. Which of the following load resistors would have the most power delivered to it when connected across the battery?

Accepted Answer

A) 1.4 Ω 
B) 2.0 Ω 
C) 4.0 Ω 
D) 8.0 Ω 
E) 16 Ω 
A) 1.4 Ω 
B) 2.0 Ω 
C) 4.0 Ω 
D) 8.0 Ω 
E) 16 Ω

Question 6

In an RC circuit, what fraction of the final energy is stored in an initially uncharged capacitor after it has been charging for 3.0 time constants?

Accepted Answer

A) 0.84 
B) 0.90 
C) 0.75 
D) 0.60 
E) 0.03 
A) 0.84 
B) 0.90 
C) 0.75 
D) 0.60 
E) 0.03

Question 7

When a 20-V emf is placed across two resistors in series, a current of 2.0 A is present in each of the resistors. When the same emf is placed across the same two resistors in parallel, the current through the emf is 10 A. What is the magnitude of the greater of the two resistances?

Accepted Answer

A) 7.2 Ω 
B) 7.6 Ω 
C) 6.9 Ω 
D) 8.0 Ω 
E) 2.8 Ω 
A) 7.2 Ω 
B) 7.6 Ω 
C) 6.9 Ω 
D) 8.0 Ω 
E) 2.8 Ω

Question 8

If I = 0.40 A in the circuit segment shown below, what is the potential difference Va − Vb?

Accepted Answer

A) 31 V 
B) 28 V 
C) 25 V 
D) 34 V 
E) 10 V 
A) 31 V 
B) 28 V 
C) 25 V 
D) 34 V 
E) 10 V

Question 9

At t = 0 the switch S is closed with the capacitor uncharged. If C = 40 μF, ε = 50 V, and R = 5.0 kΩ, how much energy is stored by the capacitor when I = 2.0 mA?

Accepted Answer

A) 20 mJ 
B) 28 mJ 
C) 32 mJ 
D) 36 mJ 
E) 40 mJ 
A) 20 mJ 
B) 28 mJ 
C) 32 mJ 
D) 36 mJ 
E) 40 mJ

Question 10

What is the equivalent resistance between points A and B in the figure when R = 18 Ω?

Accepted Answer

A) 48 Ω 
B) 64 Ω 
C) 80 Ω 
D) 96 Ω 
E) 110 Ω 
A) 48 Ω 
B) 64 Ω 
C) 80 Ω 
D) 96 Ω 
E) 110 Ω

Question 11

What is the maximum number of 100-W lightbulbs you can connect in parallel in a 120-V home circuit without tripping the 20-A circuit breaker?

Accepted Answer

The answer of What is the maximum number of 100-W...

Question 12

What is the equivalent resistance between points a and b when R = 30 Ω?

Accepted Answer

A) 27 Ω 
B) 21 Ω 
C) 24 Ω 
D) 18 Ω 
E) 7.5 Ω 
A) 27 Ω 
B) 21 Ω 
C) 24 Ω 
D) 18 Ω 
E) 7.5 Ω

Question 13

Which two circuits are exactly equivalent?

Accepted Answer

A) A and B 
B) B and C 
C) C and D 
D) D and E 
E) B and E 
A) A and B 
B) B and C 
C) C and D 
D) D and E 
E) B and E

Question 14

What is the equivalent resistance between points a and b?

Accepted Answer

A) 14 Ω 
B) 8.0 Ω 
C) 6.0 Ω 
D) 25 Ω 
E) 40 Ω 
A) 14 Ω 
B) 8.0 Ω 
C) 6.0 Ω 
D) 25 Ω 
E) 40 Ω

Question 15

At t = 0 the switch S is closed with the capacitor uncharged. If C = 30 μF, ε = 50 V, and R = 10 kΩ, what is the potential difference across the capacitor when I = 2.0 mA?

Accepted Answer

A) 20 V 
B) 15 V 
C) 25 V 
D) 30 V 
E) 45 V 
A) 20 V 
B) 15 V 
C) 25 V 
D) 30 V 
E) 45 V

Question 16

The circuit below contains three 100-W light bulbs. The emf ε = 110 V. Which light bulb(s) is(are) brightest?

Accepted Answer

A) A 
B) B 
C) C 
D) B and C 
E) All three are equally bright. 
A) A 
B) B 
C) C 
D) B and C 
E) All three are equally bright.

Question 17

What is the equivalent resistance between points A and B in the figure when R = 20 Ω?

Accepted Answer

A) 77 Ω 
B) 63 Ω 
C) 70 Ω 
D) 84 Ω 
E) 140 Ω 
A) 77 Ω 
B) 63 Ω 
C) 70 Ω 
D) 84 Ω 
E) 140 Ω

Question 18

At what rate is power supplied by the 10-V emf shown below?

Accepted Answer

A) −10 W 
B) +10 W 
C) zero 
D) +20 W 
E) −20 W 
A) −10 W 
B) +10 W 
C) zero 
D) +20 W 
E) −20 W

Question 19

The circuit below contains three 100-watt light bulbs. The emf ε = 110 V. Which light bulb(s) is(are) the brightest?

Accepted Answer

A) A 
B) B 
C) C 
D) B and C 
E) All three are equally bright. 
A) A 
B) B 
C) C 
D) B and C 
E) All three are equally bright.

Question 20

What is the equivalent resistance between points a and b when R = 13 Ω?

Accepted Answer

A) 29 Ω 
B) 23 Ω 
C) 26 Ω 
D) 20 Ω 
E) 4.6 Ω 
A) 29 Ω 
B) 23 Ω 
C) 26 Ω 
D) 20 Ω 
E) 4.6 Ω

Exam 29: Direct Current Dc Circuits

If R = 2.0 kΩ, C = 4.0 mF, ε = 8.0 V, Q = 20 mC, and I = 3.0 mA, what is the potential difference Vb − Va?

The battery is disconnected from a series RC circuit after the capacitor is fully charged and is replaced by an open switch. When the switch is closed,

The circuit below contains three 100-W light bulbs and a capacitor. The emf is 110 V and the capacitor is fully charged. Which light bulb(s) is(are) brightest?

What is the magnitude of the potential difference across the 20-Ω resistor?

A battery has an internal resistance of 4.0 Ω. Which of the following load resistors would have the most power delivered to it when connected across the battery?

In an RC circuit, what fraction of the final energy is stored in an initially uncharged capacitor after it has been charging for 3.0 time constants?

When a 20-V emf is placed across two resistors in series, a current of 2.0 A is present in each of the resistors. When the same emf is placed across the same two resistors in parallel, the current through the emf is 10 A. What is the magnitude of the greater of the two resistances?

If I = 0.40 A in the circuit segment shown below, what is the potential difference Va − Vb?

At t = 0 the switch S is closed with the capacitor uncharged. If C = 40 μF, ε = 50 V, and R = 5.0 kΩ, how much energy is stored by the capacitor when I = 2.0 mA?

What is the equivalent resistance between points A and B in the figure when R = 18 Ω?

What is the maximum number of 100-W lightbulbs you can connect in parallel in a 120-V home circuit without tripping the 20-A circuit breaker?

What is the equivalent resistance between points a and b when R = 30 Ω?

Which two circuits are exactly equivalent?

What is the equivalent resistance between points a and b?

At t = 0 the switch S is closed with the capacitor uncharged. If C = 30 μF, ε = 50 V, and R = 10 kΩ, what is the potential difference across the capacitor when I = 2.0 mA?

The circuit below contains three 100-W light bulbs. The emf ε = 110 V. Which light bulb(s) is(are) brightest?

What is the equivalent resistance between points A and B in the figure when R = 20 Ω?

At what rate is power supplied by the 10-V emf shown below?

The circuit below contains three 100-watt light bulbs. The emf ε = 110 V. Which light bulb(s) is(are) the brightest?

What is the equivalent resistance between points a and b when R = 13 Ω?

Getting Started

One-Dimensional Motion

Vectors

Two- and Three-Dimensional Motion

Newtons Laws of Motion

Applications of Newtons Laws of Motion

Gravity

Conservation of Energy

Energy in Nonisolated Systems

Systems of Particles and Conservation of Momentum

Collisions

Rotation I: Kinematics and Dynamics

Rotation II: a Conservation Approach

Static Equilibrium, Elasticity, and Fracture

Fluids

Oscillations

Traveling Waves

Superposition and Standing Waves

Temperature, Thermal Expansion, and Gas Laws

Kinetic Theory of Gases

Heat and the First Law of Thermodynamics

Entropy and the Second Law of Thermodynamics

Electric Forces

Electric Fields

Gausss Law

Electric Potential

Capacitors and Batteries

Current and Resistance

Magnetic Fields and Forces

Gausss Law for Magnetism and Amperes Law

Faradays Law of Induction

Inductors and Ac Circuits

Maxwells Equations and Electromagnetic Waves

Diffraction and Interference

Applications of the Wave Model

Reflection and Images Formed by Reflection

Refraction and Images Formed by Refraction

Relativity

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