Assertion: The quantity `L//R` possesses dimensions of time.
Reason: To reduce the rate of increases of current through a solenoide should increase the time constant `(L//R)`.

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If the assertion and reason both are false.

Answer

B

Explanation

The relation of induced emf is `e=(Ldi)/dt` and current i is given by `i=e/R=1/R*(L.di)/dtrArr(di)/dt=iR/L=i/(L//R)`.
In order to decrease the rate of increase of current through solenoid we have to increase the time constant `L/R`.