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 the assertion and reason are true and reason is a true explantion of the assertion.
B. If both the assertion and reason are true but the reason is not true the correct explantion of the assertion.
C. If the assertion is true but reason false
D. If both the assertion and reason 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.(Ldi)/(dt)`
`implies (di)/(dt) =i R/L=i/(L//R)` In order to decreases the rate of increases of current through solenoid. We have to increases the time constant `L//R`.