Question

Two solenoids of equal number of turns having their length and the radii in the same ratio 1 : 2. The ratio of their self-inductance will be

(a) 1 : 2

(b) 2 : 1

(c) 1 : 1

(d) 1 : 4

Answer 1

Correct option  (a) 1 : 2

Explanation:

For solenoids, self inductance is given by,