In a purely resistive ac circuit, what is the phase angle between the voltage and the current?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 0
With a source \( v=v_m\sin\omega t \) across a resistor, Ohm’s law gives \( i=(v_m/R)\sin\omega t \) at every instant. The current varies with the same \( \sin\omega t \) as the voltage, so the two are in phase and the phase angle between them is zero.
NCERT (2026-27):
AC Voltage Applied to a Resistor – “… Note, in particular that both v and i reach zero, minimum and maximum values at the same time. Clearly, the voltage and current are in phase with each other.”