Question

Is it possible that potential difference across the battery should be greater than the EMF of it and then in which case
(A).Not possible
(B).Possible when the battery is discharging
(C).Possible when the battery is charging
(D).None of the above

Answer 1

Hint: The potential difference along the battery may be equal, lesser as well as greater than the EMF it depends on their conditions.

Complete answer:
When no current is drawn from the circuit then the EMF is equal to the electric potential difference. It produced the separation of the charge.
So, the option (A) is not correct.
If the battery is discharging then the, potential difference along the battery is,
V = E – IR
Here, V is the potential difference,
E is the EMF of the battery,
I is the electric current,
R is the resistance,
So, we get that when the battery is discharging then the potential difference is lesser than the EMF.
So, the option (B) is not correct.
If the battery is charging then the, potential difference along the battery is,
V = E + IR
Here, V is the potential difference,
E is the EMF of the battery,
I is the electric current,
R is the resistance,
So, we get that when the battery is charging then the potential difference is greater than the EMF.

So, the option (C) is correct.

Note:
The potential difference and the EMF are just different words for the term voltage. These words refer to the same measurement between the two terminals.
Whenever we have charge that means a rechargeable battery, then we have to apply an external voltage which is higher than the natural internal EMF.
In this case, the electric current will flow into the battery until it is charged.