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WorksheetsMagnetism & Its Uses
Total questions: 40
Worksheet time: 2hrs 45mins
Name
Class
Date
1.
The strength of an electromagnet can be increased by reducing the number of turns on the wire coil.
a)
True
b)
False
2.
When you bring the south ends of two magnets close together, they repel each other.
a)
True
b)
False
3.
An electric motor is used to change mechanical energy into electrical energy.
a)
True
b)
False
4.
Moving a wire through a magnetic field creates an electrical current in a wire.
a)
True
b)
False
5.
Before alternating current from a power plant can enter a home, its voltage must be increased.
a)
True
b)
False
6.
Paper clips and other objects that contain iron can become temporary magnets.
a)
True
b)
False
7.
A device that increases or decreases voltage in a power line is a ___.
a)
commutator
b)
generator
c)
motor
d)
transformer
8.
Current that does NOT reverse direction is called ___.
a)
alternating
b)
direct current
c)
circuit current
d)
magnetic current
9.
The location of the strongest magnetic forces is the ___.
a)
electromagnets
b)
magnetic fields
c)
magnetic domains
d)
magnetic poles
10.
Current that reverses direction in a regular pattern is called ___.
a)
alternating current
b)
direct current
c)
circuit current
d)
magnetic current
11.
The region around a magnet where the magnetic forces act is the ___.
a)
electromagnetic pole
b)
magnetic field
c)
magnetic domain
d)
temporary magnets
12.
Objects that keep their magnetic properties for a long time are called ___.
a)
electromagnets
b)
permanent magnets
c)
magnetic domains
d)
temporary magnets
13.
A device that uses an electromagnet to measure electric current is a(n) ___.
a)
galvanometer
b)
electric motor
c)
commutator
d)
generator
14.
A switch that reverses the direction of a motor is a(n) ___.
a)
galvanometer
b)
commutator
c)
electric motor
d)
generator
15.
A simple transformer consists of two coils of wire called the ___.
a)
input and output loops
b)
step-up and step-down generators
c)
alternating and direct current
d)
primary and secondary coils
16.
The function of an electric motor is to change ___.
a)
chemical energy to electrical energy
b)
electrical energy to chemical energy
c)
electrical energy to mechanical energy
d)
mechanical energy to electrical energy
17.
The function of a generator is to change ___.
a)
chemical energy to electrical energy
b)
electrical energy to chemical energy
c)
electrical energy to mechanical energy
d)
mechanical energy to electrical energy
18.
The current that flows in an electric circuit carries ___.
a)
chemical energy
b)
thermal energy
c)
mechanical energy
d)
electrical energy
19.
Electromagnetic induction is the process of producing an electric current by moving a loop of wire ___.
a)
through a magnetic field
b)
around an iron core
c)
through a magnetic domain
d)
around a magnetic pole
20.
The atoms in a magnet are ___.
a)
arranged randomly
b)
aligned according to magnetic fields
c)
negatively charged
d)
positively charged
21.
A transformer that increases voltage is a ___.
a)
resistance transformer
b)
step-down transformer
c)
step-up transformer
d)
voltage motor
22.
In the United States, power lines can carry power voltages as high as 750,000 V, a step-down transformer reduces the voltage to ___ for home use.
a)
60 V
b)
60 Hz
c)
120 V
d)
120 Hz
23.
A dry-cell battery produces ___.
a)
an alternating current
b)
a direct current
c)
the same current that a generator produces
d)
both direct and alternating current
24.
The magnetic force of a magnet is ___.
a)
the same at all parts of the magnet
b)
strongest at the center
c)
strongest at the poles
d)
weakest at the poles
25.
In a step-up transformer, the number of turns of a wire is greater in the ___ coil than the ___ coil, and the ___ voltage exceeds the ___ voltage.
a)
primary, secondary, input, output
b)
primary, secondary, output, input
c)
secondary, primary, input, output
d)
secondary, primary, output, input
26.
If a transformer has 11 turns on the primary coil and 5 turns on the secondary coil, what type of transformer is it?
a)
step-up
b)
step-down
27.
If a transformer has 11 turns on the primary coil and 5 turns on the secondary coil, what must happen with voltage output?
a)
increases
b)
decreases
28.
What is magnetic domain?
a)
atoms of a magnet are aligned in a magnet
b)
only electrons are aligned within a magnet
c)
atoms are unaligned in a magnet
d)
only protons are aligned within a mgnet
29.
What happens to magnetic domains of a temporary magnet as its magnetic field weakens?
a)
nothing, atoms remain aligned
b)
atoms gradually become unaligned
c)
atoms suddenly become unaligned
d)
only electrons change alignement
30.
Which describes how an electromagnet works?
a)
A circuit is created and coils are wrapped around an iron core to create a magnetic field.
b)
A wire is wrapped around an iron core creating an electromagnet
c)
A circuit is created and coils are wrapped around any metal to create a magnetic field.
d)
A wire is connected to a voltage source that provides electricity for current.
31.
What is the primary purpose of a motor in terms of energy?
a)
mechanical --> chemical
b)
chemical --> thermal
c)
mechanical --> electrical
d)
electrical --> mechanical
32.
What is the primary purpose of a generator in terms of energy?
a)
mechanical --> electrical
b)
electrical --> mechanical
c)
mechanical --> thermal
d)
thermal --> electrical
33.
Why would a permanent magnet that was dropped lose some of its magnetic properties?
a)
It breaks and becomes two magnets.
b)
The protons shift out of place.
c)
The magnetic domains become unaligned.
d)
The electrons only move around.
34.
Why are electromagnets temporary magnets?
a)
They are expensive to operate.
b)
They cannot operate for a long time without shorting out.
c)
They can be turned on and off.
d)
They are not powerful enough for certain jobs.
35.
Does a magnetic field exist only at a magnet's poles?
a)
Yes, the poles concentrate the magnetic field around them.
b)
No, the magnetic field is evenly distributed around the magnet.
c)
Yes, the magnetic field is unable to escape the polar regions.
d)
No, the magnetic field is stronger at the poles, but still present around the entire magnet.
36.
Is it possible to break a magnet into two pieces so one of the pieces has just one pole?
a)
Yes, if you break a bar magnet, you separate the N pole from the S pole.
b)
No, if you break a magnet, you only create two smaller magnets with both N and poles.
37.
Which elements can be used to make permanent magnets?
a)
iron, aluminum, copper
b)
copper, zinc, iron
c)
iron, nickel, cobalt
d)
gold, silver, iron
38.
How can the magnetic field of an electromagnet be increased?
a)
increase coils, decrease voltage
b)
decrease coils, increase voltage
c)
increase coils, increase voltage
d)
decrease coils, decrease voltage
39.
If the input voltage of a transformer with 60 turns on the primary coil and 4 turns on the secondary coil is 180 V, what is the output voltage?
Vp/Vs = Np/Ns
Vp/Vs = Np/Ns
a)
12 V
b)
2,700 V
c)
12 Hz
d)
2,700 Hz
40.
If the output voltage from a transformer with 60 turns on the primary coil and 4 turns on the secondary coil is 32 V, what is the input voltage?
Vp/Vs = Np/Ns
Vp/Vs = Np/Ns
a)
26.25 V
b)
0.47 V
c)
7.5 V
d)
480
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