Which of the following statements is true about an electromagnet?
| Which of the following statements is true about an electromagnet?
A. The polarity of an electromagnet cannot be changed.
B. An electromagnet produces a comparatively weak force of attraction.
C. The strength of an electromagnet can be changed by changing the number of turns in its coil.
D. An electromagnet is permanent magnet.
Please scroll down to see the correct answer and solution guide.
Right Answer is: C
SOLUTION
CONCEPT:
- An electromagnet is a temporary magnet that should ideally have the property to behave as a magnet when current passes through it and lose magnetism as soon as the current is stopped.
- Soft iron is generally used for making electromagnets because it has high magnetic permeability, i.e. it can easily gain magnetic properties when current is passed around the core and quickly lose when the current is stopped.
- The soft iron inside the coil makes the magnetic field stronger because it becomes a magnet itself when the current is flowing
EXPLANATION:
- The polarity of an electromagnet can be changed by changing the polarity of the battery. Therefore option 1 is incorrect.
- An electromagnet produces a very strong force of attraction. Therefore option 2 is incorrect.
- The strength of an electromagnet can be changed by changing the number of turns in its coil and by increasing the current through it. Therefore option 3 is correct.
- As the electromagnet is a temporary magnetic which is only working till when we give the current to it. Therefore option 4 is incorrect.
