Question

Statement 1: EMF of a battery can never be equal to potential difference across its terminals.
Statement 2: EMF and Potential Difference of a battery are completely independent.

• A. Statement 1 – true, Statement 2 – true
• B. Statement 1 – true, Statement 2 - false
• C. Statement 1 – false, Statement 2 - true
• D. Statement 1 – false, Statement 2 - false

Answer 1

The correct option is D Statement 1 – false, Statement 2 - false

Anything, which a current flows through will offer some resistance to its flow. And when current flows through such a resistance, the charges lose energy. There is a resistance that a battery offers to current and that is its internal resistance. There is a potential drop across this internal resistance and hence the total potential difference across the battery is its EMF minus the drop across internal resistance
V = E – ir
Thus if i=0, then V across the battery will be equal to the emf across the device.
Or we could say, when the battery is not connected to a circuit, the potential difference across it is equal to its emf.