A battery of emf E and internal resistance r is connected across a pure resistive device (such as an electric heater) or resistance R. Prove that the power output of the device will be maximum if R = r .

A battery of emf E and internal resistance 'r' is connected to an external resistance 'R', the condition for maximum power transfer is

A cell of emf E and internal resistance r is connected to a variable external resistor R. the graph which gives the terminal voltage of cell V with respect to R is

A battery of emf 10V and internal resistance 3 ohm is connected to a resistor. If the current in the circuit is 0.5A, what is the resistance of resistance of resistor ? What is the terminal voltage of the battery when the circuit is closed?

Two identical cells each of emf E and internal resistance r are connected in parallel with an external resistance R. To get maximum power developed across R, the value of R is

A cell of emf e and internal resistance r is connected to a variable resistance R as shown in Fig.Match the statements given-Jn Column-I with the conditions stated in Column-ll,

n electric cells of emf e and internal resistance r each are connected in series.What is the emf of this combination.

A cell of emf E and internal resistance r is connected across a variable resistor R. Plot a graph showing variation terminal voltage V of the of the cell Versus the current I. Using the plot,show how the emf of the cell and its internal resistance can be determined.

Four cells, each of emf E and internal resistance r , are connected in series across an external resistance R By mistake one of the cells is connected in reverse. Then the current in the external circuit is