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

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 batteries, one of emf 18 volts and internal resistance 2 $$\Omega $$ and the other of emf 12 volts and internal resistance 1 $$\Omega $$, are connected as shown. The voltmeter V will record a reading of

When a wire of uniform cross-section $$a$$ length $$l$$ and resistance R is bent into a complete circle. resistance between any two of diametrically opposite points will be