Question

4. A set of batteries are put into a circuit. a. Explain if/how it is possible for the terminal voltage to be less than, equal to, and/or greater than the emf of the batteries. b. Discuss how the batteries can be arranged to reduce internal resistance, and the affect this would have on the terminal voltage.

Answer 1

a.

Every battery have an internal resistance ' r ' within itself , and correspondingly a potential drop ' Ir ' in the circuit, where ' I ' is the current in the circuit.

Terminal Voltage, V = E - Ir

So, Terminal Voltage will be always less than the emf ' E '

b.

When the batteries are connected in series, the effective internal resistance increases, and consequently the potential drop increases, which leads to a lesser terminal voltage. But of the batteries are connected in parallel , the effective internal resistance decreases, and consequently the potential drop also decreases, so that we can have more terminal voltage.

So the batteries must be connected in Parallel