Given that the two resistors are connected in parallel and each resistance is 14 ohms.
The current in the circuit is I = 0.1 A.
We have to find the voltage of the battery.
Let the voltage be denoted by V.
First, we have to find the equivalent resistance.

The equivalent resistance is 7 ohm.
According to Ohm's law, the voltage can be calculated by the formula

Thus, the voltage of the battery is 0.7 V.