Question 1

A 200-Ω resistor is rated at 1/4 W.What is the maximum voltage that can safely be connected across it?

Accepted Answer

A) 0.71 V 
B) 7.1 V 
C) 50 V 
D) 0.25 V 
A) 0.71 V 
B) 7.1 V 
C) 50 V 
D) 0.25 V

Question 2

Three light bulbs,A,B,and C,have electrical ratings as follows: 
Bulb A: 96.0 W,1.70 A
Bulb B: 80.0 V,205 W
Bulb C: 120 V,0.400 A
These three bulbs are connected in a circuit across a 150-V voltage power source,as shown in the figure.Assume that the filament resistances of the light bulbs are constant and independent of operating conditions.What is the equivalent resistance of this combination of bulbs between the terminals of the power source?

Accepted Answer

A) 61.5 Ω 
B) 15.3 Ω 
C) 74.0 Ω 
D) 86.2 Ω 
E) 364 Ω 
A) 61.5 Ω 
B) 15.3 Ω 
C) 74.0 Ω 
D) 86.2 Ω 
E) 364 Ω

Question 3

Three 2.0-Ω resistors are connected to form the sides of an equilateral triangle ABC as shown in the figure.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 4

For the circuit shown in the figure,R1 = 5.6 Ω,R2 = 5.6 Ω,R3 = 14 Ω,and ε = 6.0 V,and the battery is ideal.
(a)What is the equivalent resistance across the battery?
(b)Find the current through each resistor.

Accepted Answer

(a)9.6 Ω

Question 5

How much energy does a 100-W light bulb use in 8.0 hours?

Accepted Answer

A) 0.0080 kWh 
B) 0.80 kWh 
C) 13 kWh 
D) 800 kWh 
A) 0.0080 kWh 
B) 0.80 kWh 
C) 13 kWh 
D) 800 kWh

Question 6

What is the resistance of a cylindrical metal rod 1.0 cm in diameter and 45 m long,if the resistivity of the metal is 1.4 × 10-8 Ω ∙ m?

Accepted Answer

A) 0.0063 Ω 
B) 0.0080 Ω 
C) 0.80 Ω 
D) 6.3 Ω 
A) 0.0063 Ω 
B) 0.0080 Ω 
C) 0.80 Ω 
D) 6.3 Ω

Question 7

Four resistors are connected across an ideal dc battery with voltage V as shown in the figure.Assume that all quantities shown are accurate to two significant figures.If the total current through this circuit is I = 2.0 A,what is the current through the 4.0-Ω resistor?

Accepted Answer

A) 1.0 A 
B) 2.0 A 
C) 3.0 A 
D) 1.3 A 
E) 2.4 A 
A) 1.0 A 
B) 2.0 A 
C) 3.0 A 
D) 1.3 A 
E) 2.4 A

Question 8

A jeweler needs to electroplate gold,having an atomic mass of 196.97 g/mol,onto a bracelet.He knows that the charge carriers in the ionic solution are singly-ionized gold ions,Au+,and has calculated that he must deposit $0.20 \mathrm {~g}$ of gold to reach the necessary thickness.How much current does he need to plate the bracelet in 3.0 hours? (e = 1.60 × 10-19 C,NA = 6.02 × 1023 atoms/mol)

Accepted Answer

A) 9.1 mA 
B) 540 mA 
C) 33 A 
D) 1800 mA 
A) 9.1 mA 
B) 540 mA 
C) 33 A 
D) 1800 mA

Question 9

Determine the current through the 7.0-Ω resistor for the circuit shown in the figure.Assume that the batteries are ideal and that all numbers are accurate to two significant figures.

Accepted Answer

A) 0.28 A 
B) 1.3 A 
C) 1.6 A 
D) 2.1 A 
A) 0.28 A 
B) 1.3 A 
C) 1.6 A 
D) 2.1 A

Question 10

The heating element of a toaster is a 5.4-m length of nichrome wire of diameter 0.48 mm.The resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6 Ω ∙ m.The toaster is designed to operate at a voltage of 120 V.How much power does it draw in normal operation?

Accepted Answer

A) 370 W 
B) 360 W 
C) 380 W 
D) 400 W 
E) 410 W 
A) 370 W 
B) 360 W 
C) 380 W 
D) 400 W 
E) 410 W

Question 11

A resistor is made out of a wire having a length L.When the ends of the wire are attached across the terminals of an ideal battery having a constant voltage V0 across its terminals,there is current I through the wire.If the wire were cut in half,making two wires of length L/2,and both wires were attached across the terminals of the battery (the right ends of both wires attached to one terminal,and the left ends attached to the other terminal),how much current would the battery put out?

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 12

There is a current of 5.0 A through an electrical device for 10 seconds.How many electrons flow through this device during this time? (e = 1.60 × 10-19 C)

Accepted Answer

A) 0.20 
B) 20 
C) 2.0 
D) 3.1 x $10^{20}$ 
E) 31 x $10^{20}$ 
A) 0.20 
B) 20 
C) 2.0 
D) 3.1 x $10^{20}$ 
E) 31 x $10^{20}$

Question 13

A 1.0-mm diameter extension cord is made of metal having a resistivity of 1.68 × 10-8 Ω ∙ m.When it carries a current of 15 A,what is the potential difference between two points in the cord that are 100 m apart?

Accepted Answer

A) 12 V 
B) 23 V 
C) 32 V 
D) 41 V 
A) 12 V 
B) 23 V 
C) 32 V 
D) 41 V

Question 14

A total of 2.0 × 1013 electrons pass a given point in a wire in 15 s.What is the current through the wire? (e = 1.60 × 10-19 C)

Accepted Answer

A) 1.3 mA 
B) 1.3 A 
C) 0.21 μA 
D) 3.2 μA 
A) 1.3 mA 
B) 1.3 A 
C) 0.21 μA 
D) 3.2 μA

Question 15

A 9-V battery is hooked up to two resistors in series using wires of negligible resistance.One has a resistance of 5 Ω,and the other has a resistance of 10 Ω.Several locations along the circuit are marked with letters,as shown in the figure.Which statements about this circuit are true? (There could be more than one correct choice.)

Accepted Answer

A) The current is exactly the same at points A, B, C, and D. 
B) The current at A is greater than the current at B, which is equal to the current at C, which is greater than the current at D. 
C) The current at A is greater than the current at B, which is greater than the current at C, which is greater than the current at D. 
D) The potential at B is equal to the potential at C. 
E) The potential at D is equal to the potential at C. 
A) The current is exactly the same at points A, B, C, and D. 
B) The current at A is greater than the current at B, which is equal to the current at C, which is greater than the current at D. 
C) The current at A is greater than the current at B, which is greater than the current at C, which is greater than the current at D. 
D) The potential at B is equal to the potential at C. 
E) The potential at D is equal to the potential at C.

Question 16

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 largest 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 17

The voltage drop across a metal bar is $5.0 \mathrm {~V}$ while there is a current of $10.0 \mathrm {~mA}$ through it.How much power does this bar dissipate?

Accepted Answer

A) 50 mW 
B) 500 μW 
C) 2.5 kW 
D) 0.50 kW 
A) 50 mW 
B) 500 μW 
C) 2.5 kW 
D) 0.50 kW

Question 18

The lamps in a string of decorative lights are connected in parallel across a constant-voltage power source.What happens if one lamp burns out? (Assume negligible resistance in the wires leading to the lamps.)

Accepted Answer

A) The brightness of the lamps will not change appreciably. 
B) The other lamps get brighter equally. 
C) The other lamps get brighter, but some get brighter than others. 
D) The other lamps get dimmer equally. 
E) The other lamps get dimmer, but some get dimmer than others. 
A) The brightness of the lamps will not change appreciably. 
B) The other lamps get brighter equally. 
C) The other lamps get brighter, but some get brighter than others. 
D) The other lamps get dimmer equally. 
E) The other lamps get dimmer, but some get dimmer than others.

Question 19

The current through a piece of lab equipment must be limited to 2.75 A when it is run by a 120-V dc power supply.What must be the resistance of this equipment?

Accepted Answer

The answer of The current through a piece of lab...

Question 20

For the graph shown in the figure,what physical quantity does the slope of the graph represent for ohmic material?

Accepted Answer

A) current 
B) resistivity 
C) 1/(current) 
D) power 
E) 1/(resistivity) 
A) current 
B) resistivity 
C) 1/(current) 
D) power 
E) 1/(resistivity)

Exam 17: Dc Circuits

A 200-Ω resistor is rated at 1/4 W.What is the maximum voltage that can safely be connected across it?

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

For the circuit shown in the figure,R1 = 5.6 Ω,R2 = 5.6 Ω,R3 = 14 Ω,and ε = 6.0 V,and the battery is ideal. (a)What is the equivalent resistance across the battery? (b)Find the current through each resistor.

How much energy does a 100-W light bulb use in 8.0 hours?

What is the resistance of a cylindrical metal rod 1.0 cm in diameter and 45 m long,if the resistivity of the metal is 1.4 × 10-8 Ω ∙ m?

Four resistors are connected across an ideal dc battery with voltage V as shown in the figure.Assume that all quantities shown are accurate to two significant figures.If the total current through this circuit is I = 2.0 A,what is the current through the 4.0-Ω resistor?

Determine the current through the 7.0-Ω resistor for the circuit shown in the figure.Assume that the batteries are ideal and that all numbers are accurate to two significant figures.

The heating element of a toaster is a 5.4-m length of nichrome wire of diameter 0.48 mm.The resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6 Ω ∙ m.The toaster is designed to operate at a voltage of 120 V.How much power does it draw in normal operation?

There is a current of 5.0 A through an electrical device for 10 seconds.How many electrons flow through this device during this time? (e = 1.60 × 10-19 C)

A 1.0-mm diameter extension cord is made of metal having a resistivity of 1.68 × 10-8 Ω ∙ m.When it carries a current of 15 A,what is the potential difference between two points in the cord that are 100 m apart?

A total of 2.0 × 1013 electrons pass a given point in a wire in 15 s.What is the current through the wire? (e = 1.60 × 10-19 C)

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 largest possible resistance,you should attach the leads to the opposite faces that measure

The voltage drop across a metal bar is 5.0 V5.0 \mathrm {~V}5.0 V while there is a current of 10.0 mA10.0 \mathrm {~mA}10.0 mA through it.How much power does this bar dissipate?

The lamps in a string of decorative lights are connected in parallel across a constant-voltage power source.What happens if one lamp burns out? (Assume negligible resistance in the wires leading to the lamps.)

The current through a piece of lab equipment must be limited to 2.75 A when it is run by a 120-V dc power supply.What must be the resistance of this equipment?

For the graph shown in the figure,what physical quantity does the slope of the graph represent for ohmic material?

Introduction

Kinematics: Motion in One Dimension

Newtonian Mechanics

Applying Newtons Laws

Circular Motion

Impulse and Linear Momentum

Work and Energy

Extended Bodies at Rest

Rotational Motion

Gases

Static Fluids

Fluids in Motion

First Law of Thermodynamics

Second Law of Thermodynamics

Electric Charge force and Energy

The Electric Field

Magnetism

Electromagnetic Induction

Vibrational Motion

Mechanical Waves

Reflection and Refraction

Mirrors and Lenses

Wave Optics

Electromagnetic Waves

Special Relativity

Quantum Optics

Atomic Physics

Nuclear Physics

Particle Physics

Filters

For the circuit shown in the figure,R₁ = 5.6 Ω,R₂ = 5.6 Ω,R₃ = 14 Ω,and ε = 6.0 V,and the battery is ideal. (a)What is the equivalent resistance across the battery? (b)Find the current through each resistor.

What is the resistance of a cylindrical metal rod 1.0 cm in diameter and 45 m long,if the resistivity of the metal is 1.4 × 10^-8 Ω ∙ m?

The heating element of a toaster is a 5.4-m length of nichrome wire of diameter 0.48 mm.The resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10^-6 Ω ∙ m.The toaster is designed to operate at a voltage of 120 V.How much power does it draw in normal operation?

There is a current of 5.0 A through an electrical device for 10 seconds.How many electrons flow through this device during this time? (e = 1.60 × 10^-19C)

A 1.0-mm diameter extension cord is made of metal having a resistivity of 1.68 × 10^-8 Ω ∙ m.When it carries a current of 15 A,what is the potential difference between two points in the cord that are 100 m apart?

A total of 2.0 × 10¹³ electrons pass a given point in a wire in 15 s.What is the current through the wire? (e = 1.60 × 10^-19C)

The voltage drop across a metal bar is $5.0 \mathrm {~V}$ while there is a current of $10.0 \mathrm {~mA}$ through it.How much power does this bar dissipate?