Two coils have self-inductance `L_(1) = 4mH` and `L_(2) = 1 mH` respectively. The currents in the two coils are increased at the same rate. At a certain instant of time both coils are given the same power. If `I_(1)` and `I_(2)` are the currents in the two coils, at that instant of time respectively, then the value of `(I_(1)//I_(2))` is :

Options

A. `(1)/(8)`
B. `(1)/(4)`
C. `(1)/(2)`
D. 1

Answer

B

Explanation

`|epsi|=L(dI)/(dt)`
`L=(|epsi|)/(dI//dt)=(IR)/(dI//dt)=(IP//I^(2))/(dI//dt)=(P)/(I(dI//dt))`
AS P and (dI/dt) are same for both the coils,
`:.(I_(1))/(I_(2))=(L_(2))/(L_(1))=(1)/(4)`