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. 2 henry
B. 3 henry
C. 4 henry
D. 5 henry

Answer

A

Explanation

`L_(eq_("series"))=L_(1)+L_(2)=10`
`L_(eq_("parallel"))=(L_(1)L_(2))/(L_(1)+L_(2))=2.4rArrL_(1)L_(2)=24`
Now, `(L_(1)-L_(2))^(2)+4L_(1)L_(2)=(L_(1)+L_(2))^(2)`
`rArr(L_(1)-L_(2))^(2)=100-96=4rArrL_(1)-L_(2)=2H`.