Question

The strength of an electromagnet can be increased by:
(a) reversing the directions of current
(b) using alternating current of high frequency
(c) increasing the current in the coil
(d) decreasing the number of turns of coil

April 3, 2024

Answer

(c) increasing the current in the coil

Reason — The strength of electromagnet can be increased by increasing the current in the coil.

💡 Some Related Questions

MAgnet

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.

MAgnet

State two differences between an electromagnet and a permanent magnet.

MAgnet

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. (a) Draw a circuit diagram to represent the process. (b) Label the poles of the electromagnet.

MAgnet

How is an electromagnet made? Name two factors on which the strength of the magnetic field of an electromagnet depends.

MAgnet

Name the material used for making the armature of an electric bell. Give a reason for your answer.

MAgnet

How is the working of an electric bell affected, if alternating current is used instead of direct current?

MAgnet

State two advantages of an electromagnet over a permanent magnet.

MAgnet

State two ways through which the strength of an electromagnet can be increased.

MAgnet

Figure shows a coil wound around a soft iron bar XY. (a) State the polarity at the end X and Y as the switch is pressed. (b) Suggest one way of increasing the strength of the electromagnet so formed.

MAgnet

What is an electromagnet?