Middle School: 6th, 7th and 8th Grade - Science - Electromagnets Solution - MCQGeeks.com

Q.1.

The magnetic field around a coil of wire carrying current .......

31%
Is a circular shape
0%
Is a diamond shape
0%
Is a square shape
69%
Is the same shape as around a bar magnet

Q.2.

What is the difference between an electromagnet and a permanent bar magnet?

20%
Electromagnets are stronger
70%
Electromagnets can be turned off
0%
Permanent magnets are stronger
10%
Permanent magnets can be turned off

Q.3.

The magnetic field around a straight wire carrying an electric current has .......

50%
A circular shape
0%
A diamond shape
0%
A square shape
50%
An oval shape

Q.4.

A relay uses a small current to .......

12%
Attract a magnet
25%
Repel a magnet
12%
Switch off a current
50%
Switch on a larger current

Q.5.

If the current in the wire increases, what happens to the strength of the magnetic field?

30%
It decreases
70%
It increases
0%
It stops the magnetic field
0%
No change

Q.6.

If the current direction through the wire is reversed, the direction of the magnetic field .......

88%
Is also reversed
12%
Stays in the same direction
0%
The current stops flowing
0%
There is no magnetic field

Q.7.

An electromagnet is used in a scrapyard because .......

88%
It can be turned on and off
0%
It can't be turned on and off
12%
It is stronger than a permanent magnet
0%
It is weaker than a permanent magnet

Q.8.

Which of the following is NOT true about the magnetic field around a coil of wire carrying a current?

50%
Changing the direction of the current will reverse the poles
0%
Increasing the number of coils will increase the strength
0%
Making the coil wider will increase the strength
50%
Putting an iron core into the coil will increase the strength

Q.9.

Which of the following uses an electromagnetic effect?

33%
Iron
11%
Light bulb
33%
Toaster
22%
Washing machine

Q.10.

A relay is used in .......

38%
A car ignition
38%
An electric bell
12%
An electric cooker
12%
An iron