Question

In a circuit, $3$ resistors of resistance $1.2\Omega ,$ $2\Omega ,$ $3\Omega ,$ are connected in parallel. The value of equivalent resistance is

• A. less than $1.2\Omega$
• B. greater than $1.2\Omega$
• C. between $1.2\Omega$ and $2\Omega$
• D. between $2\Omega$ and $3\Omega$

Answer 1

Answer: (A)

For parallel circuit $\frac{1}{R_{eq}}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}$
$\frac{1}{R_{eq}}=\frac{1}{1.2}+\frac{1}{2}+\frac{1}{3}$
$\frac{1}{R_{eq}}=\frac{6+3.6+2.4}{1.2\times 2\times 3}$
$\frac{1}{R_{eq}}=\frac{7.2}{12}$
$=0.6\Omega$
It is less than $1.2\Omega$