1. A switch controls ___ through a circuit.
2. The buildup of electrical charges on an
object is called ___.
3. A coil of wire wrapped around an iron
core can act as a(n) ___.
4. Materials that let charges flow through
them easily are ___.
5. Materials that do not let charges flow
through them easily are ___.
6. Electric current that rapidly changes
directions is called ___.
7. An object in a circuit that resists the flow
of electrons is called a(n) .
8. A device that changes motion into
electrical energy is a(n) ___.
9. A(n) ___ is formed when an electric
current passes through an unbroken path
of conductors.
10. The directions of the magnetic forces
around a magnet make up the ___.
alternating current
electric current
magnetic field
static electricity
Circle the letter of the best answer for
each question.
1. Which of these is an example of static
A thunder
B lightning
C clouds
D wind
2. The poles of a magnet have the
strongest attraction when they are
A unlike and close together.
B alike and close together.
C alike and far apart.
D unlike and far apart.
3. Electromagnets are found in
A electric motors, speakers, generators,
and compasses.
B microphones, generators, magnetic
fields, and electric motors.
C generators, electric motors,
microphones, and speakers.
D speakers, iron cores, electric motors,
and generators.
14. What unit is used to measure
A joules
B meters
C ohms
D volts
15. An electric circuit that produces a
magnetic field is called a(n)
A current.
B magnet.
C coil.
D electromagnet.
1. Which of these is a good conductor?
A copper
B plastic
C rubber
D wood
2. Study the following chart.
2. A type of circuit that has more than one
conductive path is a
A parallel circuit.
B series circuit.
C short circuit.
D switch.
3. Which unit is used to measure electrical
A watt
B amp
C volt
D ohm
4. A wire that breaks if too much current
flows through it is called a(n)
A switch.
B fuse.
C surge protector.
D ampere.
Which event does the chart describe?
A electric shock
B lightning strike
C thunderstorm
D tornado
3. Which charge does an object have
when positive and negative charges are
A static
B negative
C neutral
D positive
4. Why are negative charges more likely to
build up when objects are rubbed
A Negative particles flow more easily.
B Positive particles do move.
C There are more negative charges.
D The two objects both
Circle the letter of the best answer for
each question.
1. Resistance to electricity is measured in
A watts.
B amps.
C volts.
D ohms.
1. An electromagnet works because
A moving electrons generate magnetic
B alternating current completes a circuit.
C a generator is powerful.
D protons flow through copper wire.
2. An electromagnet is different from a
permanent magnet because an
A is magnetic.
B can push and pull.
C can attract some metals.
D can turn on and off.
3. A device that creates electric current by
spinning an electric coil between the poles
of a powerful magnet is a(n)
A electric motor.
B electromagnet.
C generator.
D maglev train.
4. A device that lowers the voltage of
electricity is called
A a resistor.
B a turbine.
C a transformer
D a generator.
Write the word or words that best complete
each sentence in the spaces below. Words
may be used only once.
1. The flow of electrons through a circuit
creates ___.
2. A light bulb is an example of a(n) ___.
3. When objects rub together and
electrons are transferred from one object
to the other, ___ forms.
4. Electric current that rapidly changes
directions is called ___.
5. For electricity to flow, it must follow a
complete path called a(n) ___.
6. Wrapping a coil of wire around a metal
rod is a simple way to make a(n) ___.
7. Metals such as copper and silver are
good ___ .
8. Materials such as wood and plastic are
good ___.
9. Two metals that can push or pull each
other have ___.
10. A(n) converts mechanical energy into
A. alternating current
B. circuit
C. conductors
D. electric current
E. electromagnet
F. generator
G. insulators
H. magnetism
I. resistor
J. static electricity
Circle the letter of the best answer for
each question.
11. A short circuit results when
A voltage is too low.
B current has little resistance.
C a transformer slows down.
D a motor turns on.
12. What unit is used to measure electrical
A ohms
B joules
C volts
D meters
13. When a permanent magnet is placed
near a piece of metal,
A the permanent reverses poles.
B the piece of metal takes away the
magnetic field.
C the piece of metal becomes a temporary
D the permanent magnet becomes a
temporary magnet.
14. All of the following are examples of
devices that use electromagnets except
A a doorbell
B a refrigerator magnet
C a television set
D an electric motor
15. Electrical energy that reaches homes
and factories is first produced in
A an electrical charge.
B a production station.
C a power plant.
D a transformer.