Choose the incorrect statements from the options given below:(A) SI u…

The correct answer is Option (3) → (B) and (C) only

The reactances depend on the angular frequency \( \omega = 2\pi f \) in opposite ways. The question asks for the incorrect statements, so each statement is judged as true or false.

    \( \displaystyle X_L = \omega L = 2\pi f L \qquad X_C = \frac{1}{\omega C} = \frac{1}{2\pi f C} \)

(A) SI unit of inductive reactance and capacitive reactance is ohm — Correct. Both reactances are ratios of voltage to current (\( V_0 = I_0 X \)), so both are measured in ohm.

(B) Inductive reactance acting like resistance, stops the dc and ac both — Incorrect. For dc, \( f = 0 \), so \( X_L = 0 \): an inductor passes steady dc freely and opposes only ac.

(C) Inductive reactance and capacitive reactance both are proportional to frequency of ac supply — Incorrect. Only \( X_L \) is proportional to \( f \); \( X_C \) is inversely proportional to \( f \).

(D) There is no power consumption in pure capacitive reactance. — Correct. In a pure capacitor the current leads the voltage by \( \pi/2 \), so the average power \( P = V_{\mathrm{rms}} I_{\mathrm{rms}} \cos\phi \) is zero because \( \cos 90^\circ = 0 \).

NCERT (2026-27):
AC Voltage Applied to an Inductor – “… The dimension of inductive reactance is the same as that of resistance and its SI unit is ohm (Ω). … The inductive reactance is directly proportional to the inductance and to the frequency of the current.”

AC Voltage Applied to a Capacitor – “… The dimension of capacitive reactance is the same as that of resistance and its SI unit is ohm (Ω). … But it is inversely proportional to the frequency and the capacitance.”

Power in AC Circuit: The Power Factor – “… Case (ii) Purely inductive or capacitive circuit: … Therefore, cos φ = 0, and no power is dissipated even though a current is flowing in the circuit.”