The total power dissipated in watt in the circuit shown here is

Three resistances, P, Q, R each of 2$$\Omega $$ and an unknown resistance S from the four arms of a Wheatstone bridge circuit. When a resistance of 6 $$\Omega $$ is connected in parallel to S the bridge gets balanced. What is the value of S?

Power dissipated across the 8 $$\Omega $$ resistor in the circuit shown here is 2 watt. The power dissipated in watt units across the 3 $$\Omega $$ resistor is

Two cells, having the same e.m.f. are connected in series through an external resistance R. Cells have internal resistances r₁ and r₂ (r₁ > r₂) respectively. When the circuit is closed, the potential difference across the first cell is zero. The value of R is