The emf of a battery is 21 volt. When it sends a current of 1 ampere through an external resistance, the P.D. across its terminalsfalls to 19 volt. What is the internal resistance of battery?

A lead resistance R is connected across a cell of emf E and internal resistance r. If the closed circuit p.d. across the terminals of the cell is V the internal resistance of the cell is.

A 50V battery is connected across a 10 ohm resistor. The current is 4.5 amperes. The internal resistance of the battery is

A current of 150 mA flows through a wire when the potential difference between its ends is 300 volt. Calculate the resistance of the wire,

Two cells of emf 1.5 Volt and 2 Volt having respective internal resistances of 1 Omega and 2 Omega are connected in parallel so asto send current in same direction through an external resistance of 5 Omega . Find the current through the external resistance.

Choose correct alternative. emf of a cell is 2.2 volt. When resistance R = 5 Omega is connected in series potential drop across the cell becomes 1.8 volt. Value of internal resistance of the cell is

A Cell sends a current of 0.5 A through a 2 Omega resistance. If the resistance is increased by 5 Omega , the current falls to 0.25 A. Find the emf of the cell and its internal resistance.

The emf of a cell is E volt and internal resistance is r ohm. It resistance in the external circuit is r ohm, the p.d. across the cell will be

A battery of emf 4 volt and internal resistance 1 Omega is connected in parallel with another battery of emf 1 V and internal resistance 1 Omega (with their like poles connected together). The combination is used to send current through an external resistance of 2 Omega . Calculate the current through the external resistance.