Font size
Worksheets9.3 Electromagnetism
Total questions: 26
Worksheet time: 23mins
Which statement best explains why electromagnets are preferred over permanent magnets in devices like electric bells and MRI scanners?
Electromagnets are stronger than permanent magnets.
Electromagnets can be switched on and off as needed.
Permanent magnets cannot attract non-magnetic metals.
Electromagnets do not require electric current to function.
Why is steel often used in electromagnets instead of pure iron, even though both are magnetic materials?
Steel is easier to magnetise and demagnetise repeatedly.
Steel is a better conductor of electricity than iron.
Steel retains its magnetism longer than pure iron.
Steel is not magnetic unless electricity is applied.
A student reverses the current in an electromagnet's circuit. What is the most likely result?
The electromagnet becomes a permanent magnet.
The strength of the electromagnet increases.
The poles of the electromagnet are reversed.
The electromagnet stops working completely.
What is the role of the core in an electromagnet?
To insulate the coil and prevent energy loss
To store electrical energy as potential energy
To amplify the magnetic field produced by the coil
To maintain a constant magnetic field without electricity
Why does an electric bell stop ringing when the power supply is turned off?
The coil becomes a permanent magnet.
The core gets demagnetised and breaks the circuit.
The hammer continues to hit the bell from momentum.
The coil is permanently magnetised and completes the circuit.
What property distinguishes a permanent magnet from an electromagnet?
It attracts only non-magnetic materials.
It produces a stronger magnetic field.
It retains its magnetism without electricity.
It is only made of copper and aluminium.
Which action would NOT change the poles of an electromagnet?
Reversing the wire connections to the power source
Replacing the iron core with a steel core
Wrapping the coil in the opposite direction
Switching the direction of current flow
What is the main reason you cannot turn off a permanent magnet?
It is made of non-magnetic materials.
It has a magnetic field that is always present.
It requires electricity to work.
It does not have poles.
What is the correct sequence to create an electromagnet?
Place a magnet in a wire loop and apply heat.
Wrap a wire around a magnetic material and pass electric current through it.
Rub a metal object with a magnet repeatedly.
What happens to an electromagnet when the electric current is turned off?
It becomes stronger.
It remains permanently magnetised.
It loses most of its magnetism.
It changes poles automatically.
What is the purpose of the core in an electromagnet?
To carry the electric current
To convert electricity into heat
To increase the strength of the magnetic field
To insulate the wire
How can you reverse the poles of an electromagnet?
Use a thicker wire
Use a non-magnetic core
Increase the current
Reverse the current direction
Which tools can be used to determine the poles of an electromagnet?
Select all that best applies
Voltmeter
Bar magnet with known poles
Magnetic compass
Switch
Which statement best describes the function of a coil in an electromagnet?
It creates friction with the magnetic material.
It carries magnetic waves from one pole to another.
It allows current to flow and produce a magnetic field.
It stores energy in the form of heat.
A compass needle responds to a magnetic field, because the compass needle is a
generator
motor
magnet
transformer
As the strength of a magnetic field increases, the ability to attract metal objects (a) .
What conclusion can you draw from this graph?
Use the following keywords:
current, magnetic strength
This is a picture of a simple electromagnet.
How can the electromagnet be made stronger?
Select all that best applies
number of turns of coils
material of the core
Use a smaller battery.
current in the coil
"Which type of core material is best for strengthening an electromagnet?"
(a)
What happens when an electric current flows through a wire?
the wire begins to spin.
a field of gravity is created around the wire.
Nothing happens.
a magnetic field is created around the wire.
Increasing the number of coils in an electromagnet will (a) the power of the magnet.
"To make an electromagnet, you need to pass an _____ _____ through the wire."
(a)
Complete the sentence:
When the current passes through the coil, this makes the core becomes (a) .
You can reverse the poles of an electromagnet in one of two ways.
1. (a)
2. (b)
Classify two correct ways to help you identify or tell which pole (North or South) of an electromagnet.
use a magnetic compass
use a bar magnet with known poles.
use a paper map without a compass
rely solely on intuition
follow random directions from strangers
ignore the weather conditions
use a smartphone without GPS
