A bridge circuit is shown in the diagram. The equivalent resistance between A and B is

4 Ω

The correct answer is Option (1) → 4 Ω

$\text{Bridge check: } \frac{2}{4} = \frac{4}{8} = \frac{1}{2}$

$\text{Balanced bridge} \Rightarrow \text{no current through } 7\Omega$

$\text{Top branch: } 2 + 4 = 6\Omega$

$\text{Bottom branch: } 4 + 8 = 12\Omega$

$R_{\text{eq}} = \frac{6 \times 12}{6 + 12}$

$R_{\text{eq}} = \frac{72}{18} = 4\Omega$

The equivalent resistance is $4 \ \Omega$.