The current lags behind the voltage by a phase different of $\pi /2$ radian, when in the circuit is:

A cell of negligible resistance and emf $2$ volt is connected to a series combination of $2, 3$ and $5$ ohm. The potential difference in volts between the terminals of $3$-ohm resistance will be:

চিত্রে A ও B প্রান্তের তুল্য রোধ কত?