Question

The resistors of resistances $2\Omega ,4\Omega ,5\Omega$ are connected in parallel. The total resistance of the combination will be :

• A. $\frac{29}{10}\Omega$
• B. $\frac{19}{20}\Omega$
• C. $\frac{10}{20}\Omega$
• D. $\frac{20}{19}\Omega$

Answer 1

The correct option is D $\frac{20}{19}\Omega$

According to parallel combination.

$\frac{1}{R_{eq}}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}$
$=\frac{1}{2}+\frac{1}{4}+\frac{1}{5}$
$=0.5+0.25+0.2$
$=0.95\Omega$
$\therefore R_{eq}=\frac{1}{0.95}=\frac{20}{19}\Omega$