Advertisements
Advertisements
Question
State two advantages of an electromagnet over a permanent magnet.
Advertisements
Solution
- An electromagnet can produce a strong magnetic field.
- The strength of the magnetic field of an electromagnet can easily be changed by changing the current in its solenoid.
APPEARS IN
RELATED QUESTIONS
How is an electromagnet made? Name two factors on which the strength of magnetic field of the electromagnet depends.
You are required to make an electromagnet from a soft iron bar by using a cell, an insulated coil of copper wire and a switch.
- Draw a circuit diagram to represent the process.
- Label the poles of the electromagnet.
Show with the aid of a diagram how a wire is wound on a U-shaped piece of soft iron in order to make it an electromagnet. Complete the circuit diagram and label the poles of the electromagnet.
State two ways through which the strength of an electromagnet can be increased.
Name one device that uses an electromagnet.
State two differences between an electromagnet and a permanent magnet.
Why is soft iron used as the core of the electromagnet in an electric bell?
How is the working of an electric bell affected, if alternating current be used instead of direct current?
Explain, why steel is used in preference to soft iron for making permanent magnets while soft iron is used in preference to steel for making electromagnets.
Unlike magnetic poles ______ whereas like poles ______.
