Question 1

A current is flowing south along a power line. Neglecting the earth's field, the direction of the magnetic field under the power line is

Accepted Answer

A)  north. 
B)  south. 
C)  east. 
D)  west. 
A)  north. 
B)  south. 
C)  east. 
D)  west.

Question 2

The electric energy stored in a 6-V battery rated at 20 Ah is

Accepted Answer

A)  120 J. 
B)  7.2 kJ. 
C)  12 kJ. 
D)  432 kJ. 
A)  120 J. 
B)  7.2 kJ. 
C)  12 kJ. 
D)  432 kJ.

Question 3

A compass needle tends to

Accepted Answer

A)  line up perpendicular to a magnetic field. 
B)  line up parallel to a magnetic field. 
C)  turn slowly in a constant magnetic field. 
D)  point only toward the North Pole. 
A)  line up perpendicular to a magnetic field. 
B)  line up parallel to a magnetic field. 
C)  turn slowly in a constant magnetic field. 
D)  point only toward the North Pole.

Question 4

The current with which a transformer is used

Accepted Answer

A)  must be dc. 
B)  must be ac. 
C)  may be either dc or ac. 
D)  may be neither dc nor ac. 
A)  must be dc. 
B)  must be ac. 
C)  may be either dc or ac. 
D)  may be neither dc nor ac.

Question 5

When an observer moves past a stationary electric charge, she detects

Accepted Answer

A)  only an electric field. 
B)  only a magnetic field. 
C)  both an electric and a magnetic field. 
D)  Any of these choices, depending on her speed. 
A)  only an electric field. 
B)  only a magnetic field. 
C)  both an electric and a magnetic field. 
D)  Any of these choices, depending on her speed.

Question 6

The watt, the unit of power, is equal to the

Accepted Answer

A)  volt)ampere). 
B)  volt/ampere. 
C)  ampere/volt. 
D)  volt)ohm). 
A)  volt)ampere). 
B)  volt/ampere. 
C)  ampere/volt. 
D)  volt)ohm).

Question 7

A current-carrying wire is in a magnetic field with the direction of the current perpendicular to that of the field.

Accepted Answer

A)  The wire tends to move parallel to the field. 
B)  The wire tends to move perpendicular to the field. 
C)  The wire tends to turn until it is perpendicular to the field. 
D)  The wire has no tendency to move or to turn. 
A)  The wire tends to move parallel to the field. 
B)  The wire tends to move perpendicular to the field. 
C)  The wire tends to turn until it is perpendicular to the field. 
D)  The wire has no tendency to move or to turn.

Question 8

Which of the following statements is correct?

Accepted Answer

A)  Electrons carry electric currents. 
B)  The motion of electrons produces electric currents. 
C)  Moving electrons constitute electric currents. 
D)  Electric currents are carried by conductors and insulators only. 
A)  Electrons carry electric currents. 
B)  The motion of electrons produces electric currents. 
C)  Moving electrons constitute electric currents. 
D)  Electric currents are carried by conductors and insulators only.

Question 9

Two charges of +Q are 1 cm apart. If one of the charges is replaced by a charge of -Q, the magnitude of the force between them is

Accepted Answer

A)  zero. 
B)  smaller. 
C)  the same. 
D)  larger. 
A)  zero. 
B)  smaller. 
C)  the same. 
D)  larger.

Question 10

The primary coil of a transformer is connected to a source of alternating current of voltage V. The voltage of the secondary current is

Accepted Answer

A)  lower than V. 
B)  equal to V. 
C)  higher than V. 
D)  Any of these choices could be correct, depending on the ratio of turns in the transformer coils. 
A)  lower than V. 
B)  equal to V. 
C)  higher than V. 
D)  Any of these choices could be correct, depending on the ratio of turns in the transformer coils.

Question 11

When a magnetized iron bar is strongly heated, its magnetic field

Accepted Answer

A)  becomes weaker. 
B)  becomes stronger. 
C)  reverses its direction. 
D)  is unchanged. 
A)  becomes weaker. 
B)  becomes stronger. 
C)  reverses its direction. 
D)  is unchanged.

Question 12

The conventional unit of battery capacity is the ampere-hour, which is actually a unit of

Accepted Answer

A)  energy. 
B)  power. 
C)  potential difference. 
D)  electric charge. 
A)  energy. 
B)  power. 
C)  potential difference. 
D)  electric charge.

Question 13

The resistance of a 30-W, 12-V light bulb is

Accepted Answer

A)  0.21 ohms. 
B)  0.4 ohms. 
C)  2.5 ohms. 
D)  4.8 ohms. 
A)  0.21 ohms. 
B)  0.4 ohms. 
C)  2.5 ohms. 
D)  4.8 ohms.

Question 14

The electrons in an atom

Accepted Answer

A)  are bound to it permanently. 
B)  are some distance away from the nucleus. 
C)  have more mass than the nucleus. 
D)  may be positively or negatively charged. 
A)  are bound to it permanently. 
B)  are some distance away from the nucleus. 
C)  have more mass than the nucleus. 
D)  may be positively or negatively charged.

Question 15

Relative to the electric force between two protons, the gravitational force between them is

Accepted Answer

A)  weaker. 
B)  equal in magnitude. 
C)  stronger. 
D)  Any of these choices could be correct, depending on how far apart the protons are. 
A)  weaker. 
B)  equal in magnitude. 
C)  stronger. 
D)  Any of these choices could be correct, depending on how far apart the protons are.

Question 16

The volt is the unit of electric

Accepted Answer

A)  current. 
B)  potential difference. 
C)  potential energy. 
D)  resistance. 
A)  current. 
B)  potential difference. 
C)  potential energy. 
D)  resistance.

Question 17

A magnet attracts

Accepted Answer

A)  all substances. 
B)  only iron and iron alloys and repels nothing. 
C)  iron and iron alloys and repels other substances. 
D)  some substances and repels others. 
A)  all substances. 
B)  only iron and iron alloys and repels nothing. 
C)  iron and iron alloys and repels other substances. 
D)  some substances and repels others.

Question 18

Coulomb's formula F = KQ1Q2/R2 gives the force between two charges in free space. The value of K

Accepted Answer

A)  is the same under all circumstances. 
B)  is different for positive and negative charges. 
C)  depends on the masses of the charged particles. 
D)  equals the charge on the electron. 
A)  is the same under all circumstances. 
B)  is different for positive and negative charges. 
C)  depends on the masses of the charged particles. 
D)  equals the charge on the electron.

Question 19

A current-carrying wire is in a magnetic field with the direction of the current parallel to that of the field.

Accepted Answer

A)  The wire tends to move parallel to the field. 
B)  The wire tends to move perpendicular to the field. 
C)  The wire tends to turn until it is parallel to the field. 
D)  The wire has no tendency to move or to turn. 
A)  The wire tends to move parallel to the field. 
B)  The wire tends to move perpendicular to the field. 
C)  The wire tends to turn until it is parallel to the field. 
D)  The wire has no tendency to move or to turn.

Question 20

Three 12-V batteries cannot be connected to give a voltage for the set of

Accepted Answer

A)  6 V. 
B)  12 V. 
C)  24 V. 
D)  36 V. 
A)  6 V. 
B)  12 V. 
C)  24 V. 
D)  36 V.

A current is flowing south along a power line. Neglecting the earth's field, the direction of the magnetic field under the power line is

The electric energy stored in a 6-V battery rated at 20 Ah is

A compass needle tends to

The current with which a transformer is used

When an observer moves past a stationary electric charge, she detects

The watt, the unit of power, is equal to the

A current-carrying wire is in a magnetic field with the direction of the current perpendicular to that of the field.

Which of the following statements is correct?

Two charges of +Q are 1 cm apart. If one of the charges is replaced by a charge of -Q, the magnitude of the force between them is

The primary coil of a transformer is connected to a source of alternating current of voltage V. The voltage of the secondary current is

When a magnetized iron bar is strongly heated, its magnetic field

The conventional unit of battery capacity is the ampere-hour, which is actually a unit of

The resistance of a 30-W, 12-V light bulb is

The electrons in an atom

Relative to the electric force between two protons, the gravitational force between them is

The volt is the unit of electric

A magnet attracts

Coulomb's formula F = KQ₁Q₂/R² gives the force between two charges in free space. The value of K

A current-carrying wire is in a magnetic field with the direction of the current parallel to that of the field.

Three 12-V batteries cannot be connected to give a voltage for the set of

The Scientific Method

Motion

Energy

Energy and the Future

Matter and Heat

Waves

The Nucleus

The Atom

The Periodic Law

Crystals, Ions, and Solutions

Chemical Reactions

Organic Chemistry

Atmosphere and Hydrosphere

The Rock Cycle

The Evolving Earth

The Solar System

The Stars

The Universe Galaxies

Filters

Exam 6: Electricity and Magnetism

A current is flowing south along a power line. Neglecting the earth's field, the direction of the magnetic field under the power line is

The electric energy stored in a 6-V battery rated at 20 Ah is

A compass needle tends to

The current with which a transformer is used

When an observer moves past a stationary electric charge, she detects

The watt, the unit of power, is equal to the

A current-carrying wire is in a magnetic field with the direction of the current perpendicular to that of the field.

Which of the following statements is correct?

Two charges of +Q are 1 cm apart. If one of the charges is replaced by a charge of -Q, the magnitude of the force between them is

The primary coil of a transformer is connected to a source of alternating current of voltage V. The voltage of the secondary current is

When a magnetized iron bar is strongly heated, its magnetic field

The conventional unit of battery capacity is the ampere-hour, which is actually a unit of

The resistance of a 30-W, 12-V light bulb is

The electrons in an atom

Relative to the electric force between two protons, the gravitational force between them is

The volt is the unit of electric

A magnet attracts

Coulomb's formula F = KQ1Q2/R2 gives the force between two charges in free space. The value of K

A current-carrying wire is in a magnetic field with the direction of the current parallel to that of the field.

Three 12-V batteries cannot be connected to give a voltage for the set of

The Scientific Method

Motion

Energy

Energy and the Future

Matter and Heat

Waves

The Nucleus

The Atom

The Periodic Law

Crystals, Ions, and Solutions

Chemical Reactions

Organic Chemistry

Atmosphere and Hydrosphere

The Rock Cycle

The Evolving Earth

The Solar System

The Stars

The Universe Galaxies

Filters

Coulomb's formula F = KQ₁Q₂/R² gives the force between two charges in free space. The value of K