Question

Three inductors valued at 20 mH, 100 mH, and 50 mH are connected in parallel. Then their equivalent inductance is

• A. 170 mH
• B. 12.5 mH
• C. 50 mH
• D. 100 mH

Answer 1

Answer: (B)

12.5 mH

For the parallel inductances , the equivalent inductance is given by ,

$L_{eq}=\frac{1}{1/L_1+1/L_2+....+1/L_n}$

Here, $L_{eq}=\frac{1}{1/L_1+1/L_2+1/L_3}$
$=\frac{1}{1/20+1/100+1/50}$
$=\frac{1}{\frac{5+1+2}{100}}=100/8$
$=12.5mH$