The equivalent resistance across A and B is

Question

The equivalent resistance across A and B is (A) 2 Ω (B) 3 Ω (C) 4 Ω (D) 5 Ω

Tardigrade Admin · Accepted Answer

The equivalent circuit can be redrawn as
We have,

\frac{P}{Q} = \frac{R}{S}

ie,

\frac{4}{4} = \frac{4}{4}

So, the given circuit is a balanced Wheatstone's bridge.
Hence, the equivalent resistance

R_{A B} = \frac{( 4 + 4 ) \times ( 4 + 4 )}{( 4 + 4 ) + ( 4 + 4 )}

\frac{8 \times 8}{8 + 8} = \frac{64}{16} = 4Ω

Q. The equivalent resistance across A and B is