I'm little stuck on this problem.
Here we have two different resistors and two batteries of same voltage. When the switch S is closed and assuming steady state, I think that the voltage around the capacitor will be zero. Because the two positive terminals of the batteries cancel each other's voltage, and the negative terminals have zero potential as far as I understand.
Perhaps I'm missing something. Tried to simulate this circuit in Falstad simulator, and got actually that the voltage around the capacitor is ε. But I can't agree with that.
Best Answer
Let's simplify the situation...
simulate this circuit – Schematic created using CircuitLab
Now let's show the situation where they'd "cancel out" - note that the positive terminals are connected and pointing towards each other, while the negative terminals are pointing away. The voltmeter is effectively an open circuit (i.e: no current flows through it / the wires connecting to the meter are not connected to each other), and it's position in the circuit is what matters here.
simulate this circuit