Question

When is a 1.5 - VAAA battery not actually a 1.5 - V battery? That is, when do this its terminals provide a potential difference of less than 1.5 V ?

Short answer

The battery emf is less than 1.5 V when the power drop of$iR$ is there in the battery.

Step-by-step solution

Definition of Potential difference

The potential difference is defined as the work required to move the charge of unit magnitude from a point in the conductor to the other point.

Determine the when potential difference provide less than 1.5 - V .

Consider the expression for the voltage.

$V=\epsilon -iR$

Here, the voltage is the V, the emf of the battery is $\epsilon$, the current is $i$ and the resistance is R.

Here, the product of the current and the resistance are the voltage drop in the circuit and the V is the voltage available at the terminal. So the actual voltage supplied before the drops is $\epsilon$.

Therefore, the battery emf is less than 1.5 V when the power drop of $iR$is there in the battery.