A battery of e.m.f E and internal resistance r sends a current `I_1 and I_2`, when connected to an external resitance of `R_1 and R_2` respectively. Find the e.m.f and internal resistance o the battery.

A cell of emf epsilon and internal resistance r gives a current of 0.5 A with an external resistance of 12 Omega and a current of 0.25 A with an external resistance of 25 Omega. Calculate (a) internal resistance of the cell

A cell of emf epsilon and internal resistance r gives a current of 0.5 A with an external resistance of 12 Omega and a current of 0.25 A with an external resistance of 25 Omega. Calculate (b) emf of the cell.

Two cells, of e.m.f. 2E and E, and internal resistance 2 r and r respectivley are connected in parallel. Obtain the expression for the equivalent e.m.f and the internal resistance of the combination?

n cells of e.m.f E and internal resistance r are connected in series with an external resistance R . the current will increase n times that of a single cell, if

A cell of emf E and internal resistance r is connected to external resistance R_1 and R_2 and a perfect ammeter. The current in the circuit is measured in four different situations. without any external resistance in the circuit with resistance R _1 only with R_1 and R_2 in parallel combination with R_1 and R_2 in series combination the currents measured in the four cases are 0.42 A, 1.05A, 1.4A adn 4.2 A, but not necessarily in that order. Identify the currents corresponding to the four case mentioned above.

Write down the relation between the e.m.f. of a cell and its internal resitance.

A cell of emf E and internal resistance r is connected to two external resistance R_(1) " and " R_(2) and a perfect ammeter. The current in the circuit is measured in four different situations : (i) without any external resistance in the circuit

A cell of e.m.f. E an internal resistance r is connected across an external resistance R. Plot a graph showing the variation of P.D. across R, verses R.