Question 1

Distinguish between a common bar magnet and an electromagnet.

Accepted Answer

A common bar magnet is usually composed

Question 2

An electric motor and electric generator differ in

Accepted Answer

A) the roles of input and output. 
B) basic construction. 
C) size. 
D) quality. 
A) the roles of input and output. 
B) basic construction. 
C) size. 
D) quality.

Question 3

Compared with the power input to an ideal transformer, the power output is

Accepted Answer

A) greater. 
B) less. 
C) greater or less. 
D) the same. 
A) greater. 
B) less. 
C) greater or less. 
D) the same.

Question 4

A magnetic field exists in a current-carrying coil of wire

Accepted Answer

A) if it contains a piece of iron. 
B) with or without a contained piece of iron. 
C) only if the current changes. 
A) if it contains a piece of iron. 
B) with or without a contained piece of iron. 
C) only if the current changes.

Question 5

Unlike electric charges, magnetic poles cannot be

Accepted Answer

A) located. 
B) isolated. 
C) destroyed. 
A) located. 
B) isolated. 
C) destroyed.

Question 6

Earth's magnetic field affects cosmic rays by

Accepted Answer

A) deflecting them. 
B) slowing their speeds. 
C) destroying them. 
D) absorbing them. 
A) deflecting them. 
B) slowing their speeds. 
C) destroying them. 
D) absorbing them.

Question 7

Compared with the current in the primary coil of a transformer, the current in the secondary coil

Accepted Answer

A) is greater. 
B) is less. 
C) can be greater or less. 
D) none of the above 
A) is greater. 
B) is less. 
C) can be greater or less. 
D) none of the above

Question 8

An ideal transformer has 50 turns in the primary and 500 turns in the secondary. An input of 12 V will produce an output of

Accepted Answer

A) 120 V. 
B) 10 times the power input. 
C) both 
D) neither 
A) 120 V. 
B) 10 times the power input. 
C) both 
D) neither

Question 9

Magnetic field lines about a current-carrying wire

Accepted Answer

A) extend radially from the wire. 
B) circle the wire in closed loops. 
C) both 
D) neither 
A) extend radially from the wire. 
B) circle the wire in closed loops. 
C) both 
D) neither

Question 10

An electromagnet consists of a

Accepted Answer

A) bar magnet that carries an electric current. 
B) coil of wire. 
C) current-carrying coil with a piece of iron inside. 
A) bar magnet that carries an electric current. 
B) coil of wire. 
C) current-carrying coil with a piece of iron inside.

Question 11

An iron rod becomes magnetic when

Accepted Answer

A) positive ions accumulate at one end and negative ions at the other end. 
B) its atoms are aligned with positive charges on one side and negative charges on the other side. 
C) the net spins of its electrons are in the same direction. 
D) electron motion stops. 
E) none of the above 
A) positive ions accumulate at one end and negative ions at the other end. 
B) its atoms are aligned with positive charges on one side and negative charges on the other side. 
C) the net spins of its electrons are in the same direction. 
D) electron motion stops. 
E) none of the above

Question 12

A transformer has an input of 6 V and an output of 42 V. If the input is changed to 12 V, the output would be

Accepted Answer

A) 12 V. 
B) 48 V. 
C) 84 V. 
D) none of the above 
A) 12 V. 
B) 48 V. 
C) 84 V. 
D) none of the above

Question 13

Compared with the voltage input to a transformer, the voltage output can be

Accepted Answer

A) greater. 
B) less. 
C) greater or less. 
A) greater. 
B) less. 
C) greater or less.

Question 14

The rate at which a transformer transfers energy is called

Accepted Answer

A) electromagnetic induction. 
B) transformer efficiency. 
C) power. 
A) electromagnetic induction. 
B) transformer efficiency. 
C) power.

Question 15

No magnetic force acts on a current carrying wire when it

Accepted Answer

A) carries a very small current. 
B) is perpendicular to the magnetic field. 
C) either or both 
D) none of the above 
A) carries a very small current. 
B) is perpendicular to the magnetic field. 
C) either or both 
D) none of the above

Question 16

Magnet A has twice the magnetic field strength of magnet B and pulls on magnet B with a force of 100 N. The amount of force that magnet A exerts on magnet B is

Accepted Answer

A) at or about 50 N. 
B) exactly 100 N. 
C) more than 100 N. 
D) not enough information 
A) at or about 50 N. 
B) exactly 100 N. 
C) more than 100 N. 
D) not enough information

Question 17

Which force field can increase a moving electron's speed?

Accepted Answer

A) electric field 
B) magnetic field 
C) both 
D) neither 
A) electric field 
B) magnetic field 
C) both 
D) neither

Question 18

The source of all magnetism is

Accepted Answer

A) tiny bits of iron. 
B) tiny domains of aligned atoms. 
C) ferromagnetic materials. 
D) moving electric charge. 
A) tiny bits of iron. 
B) tiny domains of aligned atoms. 
C) ferromagnetic materials. 
D) moving electric charge.

Question 19

A transformer requires

Accepted Answer

A) alternating voltage. 
B) direct current. 
C) both 
D) neither 
A) alternating voltage. 
B) direct current. 
C) both 
D) neither

Question 20

When a bar magnet is broken in half, the magnetic strength of each piece is

Accepted Answer

A) less than half. 
B) about half. 
C) the same. 
D) somewhat increased. 
A) less than half. 
B) about half. 
C) the same. 
D) somewhat increased.

Exam 9: Magnetism and Electromagnetic Induction

Distinguish between a common bar magnet and an electromagnet.

An electric motor and electric generator differ in

Compared with the power input to an ideal transformer, the power output is

A magnetic field exists in a current-carrying coil of wire

Unlike electric charges, magnetic poles cannot be

Earth's magnetic field affects cosmic rays by

Compared with the current in the primary coil of a transformer, the current in the secondary coil

An ideal transformer has 50 turns in the primary and 500 turns in the secondary. An input of 12 V will produce an output of

Magnetic field lines about a current-carrying wire

An electromagnet consists of a

An iron rod becomes magnetic when

A transformer has an input of 6 V and an output of 42 V. If the input is changed to 12 V, the output would be

Compared with the voltage input to a transformer, the voltage output can be

The rate at which a transformer transfers energy is called

No magnetic force acts on a current carrying wire when it

Magnet A has twice the magnetic field strength of magnet B and pulls on magnet B with a force of 100 N. The amount of force that magnet A exerts on magnet B is

Which force field can increase a moving electron's speed?

The source of all magnetism is

A transformer requires

When a bar magnet is broken in half, the magnetic strength of each piece is

Patterns of Motion and Equilibrium

Newtons Laws of Motion

Momentum and Energy

Gravity, Projectiles, and Satellites

Fluid Mechanics

Thermal Energy and Thermodynamics

Heat Transfer and Change of Phase

Static and Current Electricity

Waves and Sound

Light

Atoms and the Periodic Table

The Atomic Nucleus and Radioactivity

Elements of Chemistry

How Atoms Bond and Molecules Attract

Mixtures

How Chemicals React

Two Classes of Chemical Reactions

Organic Compounds

Rocks and Minerals

Plate Tectonics and Earths Interior

Shaping Earths Surface

Geologic Timereading the Rock Record

The Oceans, Atmosphere, and Climatic Effects

Driving Forces of Weather

The Solar System

Stars and Galaxies

The Structure of Space and Time

Prologue: the Nature of Science

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