What happens if you cut a magnet in half?AnswersA.

it becomes demagnetized

B.

you get a separate south pole and a separate north pole

C.

you get monopoles

D.

you get two magnets

Question2.Magnetic domains are __________ in a magnet.AnswersA.

scattered

B.

aligned

C.

misaligned

D.

random

Question3.How can you make a magnet out of a long strand of wire and an iron bar?AnswersA.

Send a current through the bar.

B.

Spin the bar over the wire as a current runs through it.

C.

Wrap the wire around the bar, and send a current through it.

D.

Attach the wire to either end of the bar, and send a current through it.

Question4.How do you make an electromagnet?AnswersA.

run a current through a wire wrapped around an iron rod

B.

line up the north and south poles of a magnet with an electric wire

C.

attach a natural magnet to a battery

D.

wrap a magnet around a piece of wire with a current passing through it

Question5.

In a ferromagnetic material, the ____ act like tiny electromagnets.

AnswersA.

electrons

B.

atoms

C.

protons

D.

neutrons

Question6.If current is reduced in an electromagnet, what happens to the magnetic field strength?AnswersA.

It cancels out the magnetic field.

B.

It remains the same.

C.

It is reduced.

D.

It increases.

Question7.An iron nail that touches a magnet willAnswersA.

melt.

B.

generate an electric current.

C.

demagnetize the magnet.

D.

become polarized.

Question8.A south pole will __________ another south pole.AnswersA.

attract

B.

ignore

C.

destroy

D.

repel

Question9.According to geologic evidence, Earth's magnetic polesAnswersA.

have switched over the years.

B.

have only recently appeared.

C.

have remained the same.

D.

alternate between north and south and east and west every ten years.

Question10.The ___________ is proportional to the strength of the magnetic field.AnswersA.

mass of the magnet

B.

magnetic flux per unit area

C.

amount of space taken up by the magnet

D.

size of the magnet

Question11.The force on a current-carrying wire in a magnetic field is _____ both the direction of the magnetic field and the direction of current.AnswersA.

parallel to

B.

at right angles to

C.

opposite

D.

independent of

Question12.The magnitude of the force on a current-carrying wire in a magnetic field is proportional toAnswersA.

the strength of the field, the current in the wire, and the length of the wire in the magnetic field.

B.

the strength of the field only.

C.

the strength of the field and the current in the wire.

D.

the strength of the field, the current in the wire, and the potential difference across the wire.

Question13.The strength of a magnetic field is measured inAnswersA.

newtons.

B.

amperes.

C.

teslas.

D.

volts.

Question14.The force produced by a magnetic field on a single electron depends on what all of the following exceptAnswersA.

the velocity of the electron.

B.

the distance from the wire.

C.

the angle between the directions of the velocity and the field.

D.

the strength of the field.

Question15.Which device uses magnetic torque to measure very small amounts of unknown currents?AnswersA.

galvanometer

B.

electromagnet

C.

solenoid

D.

armature

Question16.Which of the following is an apparatus used to convert electrical energy into mechanical energy?AnswersA.

solenoid

B.

armature

C.

electrical motor

D.

galvanometer

Question17.A(n) ____ is a wire coil in an electric motor made of many loops mounted on a shaft or axle.AnswersA.

solenoid

B.

armature

C.

electromagnet

D.

ammeter

Question18.To generate a current in a wire in a magnetic field,AnswersA.

the conductor must move through the magnetic field while the magnetic field remains stationary.

B.

the magnetic field must move past the conductor while the conductor remains stationary.

C.

there must be relative movement between the wire and the magnetic field.

D.

there must be a battery connected to the wire.

Question19.EMF is measured inAnswersA.

amperes

B.

volts

C.

newtons

D.

ohms

Question20.__________ is the generation of current due to relative motion between a wire and a magnetic field.AnswersA.

Magnetic flux

B.

Electrospectrometry

C.

Electromagnetic induction

D.

Electromagnetic force

Question21.When a wire is held stationary or moved ____________ to a magnetic field, there is no current in wire.AnswersA.

parallel

B.

perpendicular

C.

tangent

D.

indirectly

Question22.Electromotive force is not a force; it is aAnswersA.

charge.

B.

current.

C.

potential difference.

D.

resistance.

Question23.The EMF produced in a wire moving in a magnetic field depends onAnswersA.

only the current in the wire.

B.

only the magnetic field strength.

C.

only the magnetic field strength, the length of the wire in the field, and the direction the wire moves.

D.

the magnetic field strength, the length of the wire in the field, and the velocity of the wire.

Question24.Which of the following statements are true for an alternating current electric generator?AnswersA.

The average power is half of the maximum power.

B.

The effective current is about 71 percent of the maximum current.

C.

The effective voltage is about 71 percent of the maximum voltage.

D.

all of the above

Question25.The two coils in a transformer mustAnswersA.

be electrically insulated from each other.

B.

be wound around different iron cores.

C.

have the same number of windings.

D.

have the same resistance.

Question26.Transformers can change _____ with relatively little waste of energy.AnswersA.

magnetic fields

B.

power

C.

resistances

D.

voltages

Question27.An insulated coil in which varying EMF is induced isAnswersA.

a primary coil.

B.

a secondary coil.

C.

found only in step-down transformers.

D.

found only in step-up transformers.

Question28.In an ideal transformer, the electric power delivered to the secondary circuit is __________ the power supplied to the primary circuit.AnswersA.

double

B.

equal to

C.

greater than

D.

less than

Question29.In a step-up transformer, the number of loops of wire in the primary coil is ______ the number of loops in the secondary coil.AnswersA.

double

B.

equal to

C.

greater than

D.

less than

Question30.When the primary coil is connected to a source of AC voltage, the changing current produces aAnswersA.

resistance.

B.

potential difference.

C.

varying magnetic field.

D.

steady magnetic field.

Question31.____________ in home appliances adjust potential differences to usable levels.AnswersA.

Coils

B.

Magnets

C.

Transformers

D.

Currents

Question32.A(n) _____________________ is generated by a piece of metal moving through a magnetic field.AnswersA.

induced electromotive force

B.

eddy current

C.

mutual inductance

D.

self-inductance

Question33.The heavy current required when a motor starts can cause ______ in the wires that carry current to the motor.AnswersA.

a drop in electric potential

B.

a surge in electric potential

C.

an eddy current

D.

mutual inductance

Question34.The induction of EMF in a wire carrying a changing current is an example ofAnswersA.

self-inductance.

B.

mutual inductance.

C.

an eddy current.

D.

a step-up transformer.

Question35.Isotopes are atoms of the same element, which have differentAnswersA.

chemical properties.

B.

numbers of electrons.

C.

numbers of protons.

D.

masses.

Question36.The mass of an electron is determined byAnswersA.

multiplying the velocity of the electron by the strength of the magnetic field.

B.

weighing individual electrons on a balance inside a vacuum.

C.

finding the charge-to-mass ratio and calculating the mass.

D.

multiplying the strength of the electric field by the charge on the electron.

Question37.The charge-to-mass ratio of an electron in a Thomson tube is represented by which equation?AnswersA.

q/m = Bqv

B.

q/m = Br/v

C.

m/q = v/Br

D.

q/m = v/Br

Question38.In a spectrometer, a magnet causes the positive ions to be deflected according to theirAnswersA.

mass.

B.

charge.

C.

electron configuration.

D.

velocity.

Question39.Why did Thompson observe two glowing dots when he put neon gas into a cathode-ray tube?AnswersA.

The neon contained impurities.

B.

The neon was made up of two different isotopes whose atoms had different chemical properties.

C.

The neon was made up of two different isotopes whose atoms had different masses.

D.

The neon was made up of two different isotopes whose atoms had different charges.

Question40.Ions in a mass spectrometer follow a ___________ path as they pass through a magnetic field.AnswersA.

parallel

B.

circular

C.

straight

D.

perpendicular

Question41.Induction is a process in which a moving ___________ produces a(n) ___________ .AnswersA.

magnetic field, electric field

B.

wave, electric field

C.

magnet, electric charge

D.

charge, current

Question42.An alternating current source produces changing currents in a wire connected to it. This wire generates electromagnetic fields. What is this wire called?AnswersA.

an oscillator

B.

an antenna

C.

a capacitor

D.

a polarizer

Question43.Which of the following types of electromagnetic radiation has the lowest frequency?AnswersA.

red light

B.

microwaves

C.

X-rays

D.

ultraviolet light

Question44.As the wavelength of an electromagnetic wave _________ , the frequency of the wave __________.AnswersA.

increases, increases

B.

decreases, decreases

C.

increases, decreases

D.

decreases, stays the same

Question45.The speed of an electromagnetic wave in any material is determined by the ___________ of that material.AnswersA.

thickness

B.

density

C.

dielectric constant

D.

electrical resistance

Question46.A coil-and-capacitor circuit can transmit electromagnetic waves when it is connected toa(n)AnswersA.

pendulum.

B.

capacitor.

C.

magnetic field.

D.

antenna.

Question47.When a piezoelectric crystal is bent, it produces a(n) ____________ that can be used to allow the material to keep vibrating.AnswersA.

EMF

B.

current

C.

electric charge

D.

magnetic field

Question48.Thomson calculated the mass of the electron using a cathode-ray tube and a proton beam.AnswersA.

True

B.

False

Question49.X-rays carry more energy than radio waves because waves carry more energy as wavelength increases.AnswersA.

True

B.

False

Question50.The speed of an electromagnetic wave is the product of the wavelength and the frequency of the wave.AnswersA.

True

B.

False

just need letter answers no explanation