question_answer

Time constant of L-R circuit will be

A) \[\frac{L}{R}\]

B) \[\frac{2L}{R}\]

C)             \[\frac{L}{2R}\]

D)             None of these

Correct Answer: C

Solution :

[c] A circuit equivalent to the given circuit can be drawn as follows:    Where        \[{{R}_{eq}}=R+\frac{2R\times 2R}{4R}\]          \[=R+R\] \[{{R}_{eq}}=2R\] \[\therefore \]   Time constant \[=\frac{L}{2R}\]