The equivalent inductance of two inductances is `2.4` henry when connected in parallel and `10` henry when connected in series. The difference between the two inductance is

Options

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

Answer

B

Explanation

In series connection `L_(1)+L_(2)=10 H " ".....(ii)`
and in parallel connection `(L_(1)L_(2))/((L_(1)+L_(2)))=2.4H" "...(ii)`
Subsitituting the vlaue of `(L_(1)+L_(2))` form (i) into, (ii), we get
`L_(1)L_(2)=(2.4)(L_(1)+L_(2))=2.4xx10=24`
`(L_(1)L_(2))=(L_(1)+L_(2))^(2)-4L_(1)L_(2)`
`L_(1)-L_(2)=[(10)^(2)-4xx24]^(1//2)=2H" "...(iii)`
Solvin (i) and (iii), we get
`L_(1)=6H,L_(2)=4H`