In an a.c. circuit the voltage applied is E = E₀sin ω t. The resulting current in the circuit is I = I₀sin (ω t - π/2). The power consumption in the circuit is given by (a) P = √(2)E₀ I₀ (b) P = (E₀ I₀)/(√(2)) (c) P = zero (d) P = (E₀ I₀)/(2)

Answer: (c). Current lags voltage by φ = π/2. P = (E₀I₀)/(2)cos 90° = 0 So the answer is (c) P = zero.

In an a.c. circuit the voltage applied is E = E₀sin ω t. The… | JEE Main 2007 (AIEEE)

Q76JEE Main 2007 · AIEEEEasy

Power, Power Factor & Wattless Current

In an $\text{a.c.}$ circuit the voltage applied is $E = E_0\sin\omega t.$ The resulting current in the circuit is $I = I_0\sin\left(\omega t - \frac{\pi}{2}\right).$ The power consumption in the circuit is given by

Show answer and solution

Answer: (c)

Current lags voltage by $\phi = \frac{\pi}{2}$ .
$P = \frac{E_0I_0}{2}\cos 90^\circ = 0$
So the answer is (c) $P = \text{zero}$ .

Report a mistake

Power, Power Factor & Wattless Current question from JEE Main 2007 (AIEEE)

More questions on Power, Power Factor & Wattless Current