Given below are two statements; one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: Electromagnets are made of soft iron.
Reason R: Soft iron has high permeability and low retentivity.
In the light of above, statements, choose the most appropriate answer from the options given below.
Assertion A: Electromagnets are made of soft iron.
Reason R: Soft iron has high permeability and low retentivity.
In the light of above, statements, choose the most appropriate answer from the options given below.
- (A)A is not correct but R is correct
- (B)Both A and R are correct and R is the correct explanation of A✓ Correct
- (C)Both A and R are correct but R is NOT the correct explanation of A
- (D)A is correct but R is not correct
Answer: (B)
Solution
Electromagnets are made of soft iron, so the assertion is correct. Soft iron has high permeability, which lets it acquire a strong magnetisation for a given magnetising current, and low retentivity, so it loses that magnetisation almost entirely once the current stops; the reason is therefore also correct. These are exactly the properties an electromagnet needs, namely a strong field while energised and no residual field when switched off, so the reason is the correct explanation of the assertion. Both the assertion and the reason are correct and the reason is the correct explanation of the assertion.
JEE Main · 2023 · 08 Apr 2023 · Shift 2 · Single correct option