Question

If the equivalent resistance between the terminal points $P$ and $Q$ is $4\Omega$ in the given circuit, then find out the resistance of $R$ in ohms

• A. $7$
• B. $4$
• C. $2$
• D. $5$

Answer 1

Answer: (A)

Equivalent circuit is,

Therefore equivalent resistance is,
$R_{e q}=\frac{R \left(\frac{4 R}{3}\right)}{R + \frac{4 R}{3}}$
$4=\frac{4 R}{7}$
$R=7\Omega$