Question 1

A wire of length L is uniformly stretched to triple its original length.By what factor does its resistance change?

Accepted Answer

A)  1,i.e. ,no change 
B)  3 
C)  9 
D) 
  
A)  1,i.e. ,no change 
B)  3 
C)  9 
D) 
  C

Question 2

Three resistors connected in parallel have individual values of 4.0,6.0,and 10.0 Ω,respectively.If this combination is connected in series with a 12-V battery and a 2.0-Ω resistor,what is the current in the 6.0-Ω resistor?

Accepted Answer

A)  0.98 A 
B)  16 A 
C)  0.59 A 
D)  11 A 
A)  0.98 A 
B)  16 A 
C)  0.59 A 
D)  11 A A

Question 3

Resistors of values 8.0 Ω,12.0 Ω,and 24.0 Ω are connected in parallel across a fresh battery.Which resistor dissipates the least power?

Accepted Answer

A)  the 24.0-Ω resistor 
B)  All dissipate the same power when in parallel. 
C)  the 12.0-Ω resistor 
D)  the 8.0-Ω resistor 
A)  the 24.0-Ω resistor 
B)  All dissipate the same power when in parallel. 
C)  the 12.0-Ω resistor 
D)  the 8.0-Ω resistor A

Question 4

If the current in a wire is halved,what effect does this have on the electron drift velocity in the wire?

Accepted Answer

A)  It decreases by a factor of two. 
B)  It increases by a factor of four. 
C)  It stays the same. 
D)  It doubles. 
A)  It decreases by a factor of two. 
B)  It increases by a factor of four. 
C)  It stays the same. 
D)  It doubles.

Question 5

To measure the current through and the voltage across a resistor in a circuit,you should place the ammeter in _____ with the resistor and the voltmeter in _____ with the resistor.

Accepted Answer

A)  series,series 
B)  parallel,series 
C)  parallel,parallel 
D)  series,parallel 
A)  series,series 
B)  parallel,series 
C)  parallel,parallel 
D)  series,parallel

Question 6

Four 1.5-volt AA batteries in series power a transistor radio.If the batteries hold a total charge of 440 C,how long will they last if the radio has a resistance of 200 Ω?

Accepted Answer

A)  4.1 h 
B)  2.2 h 
C)  1.1 h 
D)  13 h 
A)  4.1 h 
B)  2.2 h 
C)  1.1 h 
D)  13 h

Question 7

A solar panel measures 80 cm × 50 cm.In direct sunlight,the panel delivers 4.8 A at 15 V.If the intensity of sunlight is 1000 W/m2,what is the efficiency of the solar panel in converting solar energy into electrical energy?

Accepted Answer

A)  12% 
B)  24% 
C)  18% 
D)  6.0% 
A)  12% 
B)  24% 
C)  18% 
D)  6.0%

Question 8

If I = 1.0 mA and the potential difference,VA - VB = +30 V in the circuit segment shown,determine the charge and polarity of the capacitor.

Accepted Answer

A)  1.0 mC,left plate is positive 
B)  3.5 mC,right plate is positive 
C)  3.5 mC,left plate is positive 
D)  1.0 mC,right plate is positive 
A)  1.0 mC,left plate is positive 
B)  3.5 mC,right plate is positive 
C)  3.5 mC,left plate is positive 
D)  1.0 mC,right plate is positive

Question 9

A high-voltage transmission line carries 500 A at 700 kV for a distance of 100 miles.If the resistance in the wire is 1 Ω/mile,what is the power loss due to resistive losses?

Accepted Answer

A)  250 MW 
B)  2.5 kW 
C)  25 MW 
D)  25 kW 
A)  250 MW 
B)  2.5 kW 
C)  25 MW 
D)  25 kW

Question 10

A length L of wire has a voltage V across its ends while a current I runs through the wire.If a voltage 3V were applied to another length of this same wire from the same coil and the same current were found to run through it,what is the length of this second wire?

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
A) 
  
B) 
  
C) 
  
D)

Question 11

A series RC circuit has a time constant of 1.5 s.The battery has a voltage of 50 V and the maximum current just after closing the switch is 500 mA.The capacitor is initially uncharged.What is the charge on the capacitor 3.0 s after the switch is closed?

Accepted Answer

A)  0.48 C 
B)  0.86 C 
C)  0.43 C 
D)  0.99 C 
A)  0.48 C 
B)  0.86 C 
C)  0.43 C 
D)  0.99 C

Question 12

The current in an electron beam in a cathode-ray tube is measured to be 280 µA.How many electrons hit the screen in 50 s? (e = 1.6 × 10−19 C)

Accepted Answer

A)  2.2 × 1011 electrons 
B)  8.8 × 1016 electrons 
C)  8.8 × 1015 electrons 
D)  2.2 × 1015 electrons 
A)  2.2 × 1011 electrons 
B)  8.8 × 1016 electrons 
C)  8.8 × 1015 electrons 
D)  2.2 × 1015 electrons

Question 13

A 0.10-m long metal rod has a radius of 1.0 cm and a resistance of 3.2 × 10−5 Ω.What is the resistivity of the metal?

Accepted Answer

A)  5.0 × 10−8 Ω⋅m 
B)  160 × 10−8 Ω⋅m 
C)  10 × 10−8 Ω⋅m 
D)  1.6 × 10−8 Ω⋅m 
A)  5.0 × 10−8 Ω⋅m 
B)  160 × 10−8 Ω⋅m 
C)  10 × 10−8 Ω⋅m 
D)  1.6 × 10−8 Ω⋅m

Question 14

In a circuit involving resistance and capacitance,which of the following choices would result in the longest time constant?

Accepted Answer

A)  R = 100 Ω,C = 30 μF 
B)  R = 300 Ω,C = 150 μF 
C)  R = 75 Ω,C = 75 μF 
D)  R = 200 Ω,C = 200 μF 
A)  R = 100 Ω,C = 30 μF 
B)  R = 300 Ω,C = 150 μF 
C)  R = 75 Ω,C = 75 μF 
D)  R = 200 Ω,C = 200 μF

Question 15

In order for a circuit to respond quickly,its time constant should be short.In a circuit involving resistance and capacitance,which of the following choices would result in the shortest time constant?

Accepted Answer

A)  R = 75 Ω,C = 75 μF 
B)  R = 200 Ω,C = 200 μF 
C)  R = 300 Ω,C = 75 μF 
D)  R = 100 Ω,C = 30 μF 
A)  R = 75 Ω,C = 75 μF 
B)  R = 200 Ω,C = 200 μF 
C)  R = 300 Ω,C = 75 μF 
D)  R = 100 Ω,C = 30 μF

Question 16

A battery has an internal resistance Rint.Connecting a wire of negligible resistance between the terminals of the battery draws the maximum current I​max from this battery.If instead a resistor is connected between the terminals,a smaller current is produced.What value resistor placed across the terminals would result in the current produced to be half of I​max?

Accepted Answer

A)  0.63Rint 
B)  Rint 
C)  0.50Rint 
D)  0.37Rint 
A)  0.63Rint 
B)  Rint 
C)  0.50Rint 
D)  0.37Rint

Question 17

Three resistors,each of different value,are used in a circuit with a power source supplying 12 volts.For which of the following resistor combinations is the total power supplied the greatest?

Accepted Answer

A)  This cannot be found until it is known which resistor is in series with the parallel pair. 
B)  all three resistors in series 
C)  two of the resistors in parallel with the third resistor in series with the parallel pair 
D)  all three resistors in parallel 
A)  This cannot be found until it is known which resistor is in series with the parallel pair. 
B)  all three resistors in series 
C)  two of the resistors in parallel with the third resistor in series with the parallel pair 
D)  all three resistors in parallel

Question 18

If a 9.0-V battery,with negligible internal resistance,and an 27-Ω resistor are connected in series,what is the amount of electrical energy transformed to heat per coulomb of charge that flows through the circuit?

Accepted Answer

A)  0.50 J 
B)  9.0 J 
C)  3.0 J 
D)  72 J 
A)  0.50 J 
B)  9.0 J 
C)  3.0 J 
D)  72 J

Question 19

Four 8.0-Ω resistors are connected in parallel.What is their equivalent resistance?

Accepted Answer

A)  4.0 Ω 
B)  0.50 Ω 
C)  2.0 Ω 
D)  32 Ω 
A)  4.0 Ω 
B)  0.50 Ω 
C)  2.0 Ω 
D)  32 Ω

Question 20

If a metallic wire of cross-sectional area 3.0 × 10−6 m2 carries a current of 9.1 A and has a mobile charge density of 4.24 × 1028 carriers/m3,what is the average drift velocity of the mobile charge carriers? (charge value = 1.6 × 10−19 C)

Accepted Answer

A)  3.4 × 103 m/s 
B)  1.7 × 103 m/s 
C)  4.5 × 10−4 m/s 
D)  1.5 × 10−4 m/s 
A)  3.4 × 103 m/s 
B)  1.7 × 103 m/s 
C)  4.5 × 10−4 m/s 
D)  1.5 × 10−4 m/s

Exam 19: Magnetism Magnets: Part A

A wire of length L is uniformly stretched to triple its original length.By what factor does its resistance change?

Three resistors connected in parallel have individual values of 4.0,6.0,and 10.0 Ω,respectively.If this combination is connected in series with a 12-V battery and a 2.0-Ω resistor,what is the current in the 6.0-Ω resistor?

Resistors of values 8.0 Ω,12.0 Ω,and 24.0 Ω are connected in parallel across a fresh battery.Which resistor dissipates the least power?

If the current in a wire is halved,what effect does this have on the electron drift velocity in the wire?

To measure the current through and the voltage across a resistor in a circuit,you should place the ammeter in _____ with the resistor and the voltmeter in _____ with the resistor.

Four 1.5-volt AA batteries in series power a transistor radio.If the batteries hold a total charge of 440 C,how long will they last if the radio has a resistance of 200 Ω?

A solar panel measures 80 cm × 50 cm.In direct sunlight,the panel delivers 4.8 A at 15 V.If the intensity of sunlight is 1000 W/m2,what is the efficiency of the solar panel in converting solar energy into electrical energy?

If I = 1.0 mA and the potential difference,VA - VB = +30 V in the circuit segment shown,determine the charge and polarity of the capacitor.

A high-voltage transmission line carries 500 A at 700 kV for a distance of 100 miles.If the resistance in the wire is 1 Ω/mile,what is the power loss due to resistive losses?

A length L of wire has a voltage V across its ends while a current I runs through the wire.If a voltage 3V were applied to another length of this same wire from the same coil and the same current were found to run through it,what is the length of this second wire?

A series RC circuit has a time constant of 1.5 s.The battery has a voltage of 50 V and the maximum current just after closing the switch is 500 mA.The capacitor is initially uncharged.What is the charge on the capacitor 3.0 s after the switch is closed?

The current in an electron beam in a cathode-ray tube is measured to be 280 µA.How many electrons hit the screen in 50 s? (e = 1.6 × 10−19 C)

A 0.10-m long metal rod has a radius of 1.0 cm and a resistance of 3.2 × 10−5 Ω.What is the resistivity of the metal?

In a circuit involving resistance and capacitance,which of the following choices would result in the longest time constant?

In order for a circuit to respond quickly,its time constant should be short.In a circuit involving resistance and capacitance,which of the following choices would result in the shortest time constant?

Three resistors,each of different value,are used in a circuit with a power source supplying 12 volts.For which of the following resistor combinations is the total power supplied the greatest?

If a 9.0-V battery,with negligible internal resistance,and an 27-Ω resistor are connected in series,what is the amount of electrical energy transformed to heat per coulomb of charge that flows through the circuit?

Four 8.0-Ω resistors are connected in parallel.What is their equivalent resistance?

If a metallic wire of cross-sectional area 3.0 × 10−6 m2 carries a current of 9.1 A and has a mobile charge density of 4.24 × 1028 carriers/m3,what is the average drift velocity of the mobile charge carriers? (charge value = 1.6 × 10−19 C)

Introduction

Introduction: Part A

Motion in One Dimension

Motion in One Dimension: Part A

Vectors and Two-Dimensional Motion

Vectors and Two-Dimensional Motion: Part A

The Laws of Motion

The Laws of Motion: Part A

Energy

Energy: Part A

Momentum and Collisions

Momentum and Collisions: Part A

Rotational Motion and the Law of Gravity

Rotational Motion and the Law of Gravity: Part A

Rotational Equilibrium and Rotational Dynamics

Rotational Equilibrium and Rotational Dynamics: Part A

Solids and Fluids

Solids and Fluids: Part A

Thermal Physics

Thermal Physics: Part A

Energy in Thermal Processes Heat and Internal Energy

Energy in Thermal Processes Heat and Internal Energy: Part A

The Laws of Thermodynamics Work in Thermodynamic Processes

The Laws of Thermodynamics Work in Thermodynamic Processes: Part A

Vibrations and Waves

Vibrations and Waves: Part A

Sound

Sound: Part A

Electric Forces and Electric Fields

Electric Forces and Electric Fields: Part A

Electrical Energy and Capacitance

Electrical Energy and Capacitance: Part A

Current and Resistance Electric Current

Current and Resistance Electric Current: Part A

Direct-Current Circuits Sources of EMF

Direct-Current Circuits Sources of EMF: Part A

Magnetism Magnets

Induced Voltages and Inductance

Induced Voltages and Inductance: Part A

Alternating-Current Circuits and Electromagnetic Waves

Alternating-Current Circuits and Electromagnetic Waves: Part A

Reflection and Refraction of Light

Reflection and Refraction of Light: Part A

Mirrors and Lenses

Mirrors and Lenses: Part A

Wave Optics

Wave Optics: Part A

Optical Instruments

Optical Instruments: Part A

Relativity

Relativity: Part A

Quantum Physics Blackbody Radiation and Plancks Hypothesis

Quantum Physics Blackbody Radiation and Plancks Hypothesis: Part A

Atomic Physics

Atomic Physics: Part A

Nuclear Physics

Nuclear Physics: Part A

Nuclear Energy and Elementary Particles

Nuclear Energy and Elementary Particles: Part A

Particle Collisions, Mediating Photons, and Quark Structures: Exploring the Fundamentals of Physics

To measure the current through and the voltage across a resistor in a circuit,you should place the ammeter in _ with the resistor and the voltmeter in _ with the resistor.

A solar panel measures 80 cm × 50 cm.In direct sunlight,the panel delivers 4.8 A at 15 V.If the intensity of sunlight is 1000 W/m²,what is the efficiency of the solar panel in converting solar energy into electrical energy?

If I = 1.0 mA and the potential difference,V_A - V_B = +30 V in the circuit segment shown,determine the charge and polarity of the capacitor.

The current in an electron beam in a cathode-ray tube is measured to be 280 µA.How many electrons hit the screen in 50 s? (e = 1.6 × 10−¹⁹ C)

A 0.10-m long metal rod has a radius of 1.0 cm and a resistance of 3.2 × 10−⁵ Ω.What is the resistivity of the metal?

If a metallic wire of cross-sectional area 3.0 × 10−⁶ m² carries a current of 9.1 A and has a mobile charge density of 4.24 × 10²⁸ carriers/m³,what is the average drift velocity of the mobile charge carriers? (charge value = 1.6 × 10−¹⁹ C)