Question

A battery of e.m.f. E and internal resistance r is connected to a variable resistor R as shown here. Which one of the following is true

• A. Potential difference across the terminals of the battery is maximum when R = r
• B. Power delivered to the resistor is maximum when R = r
• C. Current in the circuit is maximum when R = r
• D. Current in the circuit is maximum when

Answer 1

Answer: (B)

Power delivered to the resistor is maximum when

R = r

Answer 2

For power to be maximum

External resistance = Equivalent internal resistance of the circuit