Question

The equivalent resistance between A and B is

• A. $R$
• B. $\frac{R}{2}$
• C. $2R$
• D. None of these

Answer 1

Answer: (B)

$\frac{R}{2}$

Converting the given circuit in the equivalent circuit as shown in figure.

Now the resistances in branches ACB and ADB form Wheatstones bridge, hence no current will flow in resistance in branch CD.

Therefore, the equivalent resistance is,

$\frac{1}{R_{eq}}=\frac{1}{R}+\frac{1}{2R}+\frac{1}{2R}$

$\frac{1}{R_{eq}}=\frac{4}{2R}$

$\therefore R_{eq}=\frac{R}{2}$