Three voltmeters are connected in a circuit as shown in diagram. Find correct relation among their readings (V₁, V₂and V₃).

The correct option is V₁ + V₂ = V₃.

To find the correct relation among the readings of the three voltmeters, we analyze their connection in the electrical circuit:
1. Voltmeters $V_1$ and $V_2$ are connected in series with each other.
2. This series combination of $V_1$ and $V_2$ is connected in parallel with the third voltmeter $V_3$.

For components connected in series, the total potential difference is the sum of the individual potential differences across each component. Thus, the total potential difference across the series combination of the first two voltmeters is:

$V_{\text{series}}=V_1+V_2$

For branches connected in parallel, the potential difference across each branch is equal. Since the series combination of $V_1$ and $V_2$ is connected in parallel across the voltmeter $V_3$, their potential differences must be equal:

$V_{\text{series}}=V_3$

Equating the two expressions, we obtain the required relation:

$V_1+V_2=V_3$