The equivalent inductance of two inductors is `2.4 H` when connected in parallel and `10 H` when connected in series then the value of inductance of two inductors ?

Options

A. 8H, 2H
B. 6H, 4H
C. 5H, 5H
D. 7H, 3H

Answer

B

Explanation

`L_1 + L_2 = 10 H` ….(i)
`(L_1L_2)/((L_1 + L_2)) = 2.4 H` …..(ii)
Substituting the value of `(L_1 + L_2)` from (i) into (ii) , we get
`L_1L_2 = (2.4)(L_1 + L_2) = 2.4 xx 10 = 24`
`(L_1 - L_2) =(L_1 + L_2)^2 -4L_1L_2`
`L_1 - L_2 = [(10)^2 - 4 xx 24]^(1//2) = 2H` .....(iii)
Solving (i) and (iii), wer get `L_1 = 6H, L_2 = 4H`