Question

Assertion :If some ferromagnetic substance is filled inside a soleniod, its coeffecient of self-induction $L$ will increase. Reason: By increasing the current in a coil its coefficient of self induction $L$ can be increased.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct

Answer 1

The correct option is C Assertion is correct but Reason is incorrect

Ferromagnetic substance will attack more number of magnetic lines through it. So flux passing through it will increase. Hence coefficient of self inductance will increase.

$L(=\frac{\mu N^{2}Area}{lenght})$ depends on number of turns in the coil radius of coil etc. It does not depend the current passing it.