Question

Find out the equivalent resistance between $A$ and $B$ in the network of resistances shown in adjoining figure.

• A. $25\Omega$
• B. $10\Omega$
• C. $5\Omega$
• D. None of these

Answer 1

The correct option is C $5\Omega$

Here $4\Omega$ and $12\Omega$ are in parallel.
$\therefore \frac{1}{4}+\frac{1}{12}$
$\Rightarrow R=\frac{4\times 12}{4+12}=3\Omega$
Similarly, $6\Omega$ and $3\Omega$ are in parallel.
$\therefore dfrac1R^{\prime }=\frac{1}{6}+\frac{1}{3}$
$\Rightarrow R^{\prime }=\frac{6\times 3}{6+3}=2\Omega$
$R$ and $R^{\prime }$ are in series.
$\therefore$ Equivalent resistance between $A$ and $B$
$=R^{\prime \prime }=R+R^{\prime }=3+2=5\Omega$.