A storage battery of emf 0.8 V and internal resistance `0.5 Omega` is being charged by a 120 V do supply using a series resistor of `15.5 Omega`. What is the terminal voltage of the battery during charging? What is the purpose of having a series resistor in the charging circuit?

A battery of emf 10 V internal resistance 3 Omega is connected to a resistor R. (i) If the current in the circuit is 0.5 A. calculate the value of R. (ii) What is the terminal voltage of the battery when the cirucit is closed.

24 cells, each of emf 1.5V and internal resistance is 2Omega connected to 12Omega series external resistance. Then,

(a) Six lead-acid type of secondary cells each of emf 2.0 V and internal resistacne 0.015Omega are joined in series to provide a supply to a resistance of 8.5 Omega. What are the current drawn from the suply and its terminal voltage ? (b) A secondary cell after long use has an emf of 1.9 V and a large internal resistance of 380 Omega. What maximum current can be drawn from the cell? Could the cell drive tghe starting motor of a car ?

A battery of emf 2.5 V and internal resistance r is connected is series with a resistor of 45 ohm through an ammeter of resistance 1 ohm. The ammeter reads a current of 50 mA. Draw the circuit diagram and calculate the value of r.