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CUET · PHYSICS · PYQ PAPER 2025

The current and voltage in an a. c. circuit are given as
\( I = 50 \sin(50t) \text{ mA} \),
\( V = 100 \sin(50t + \pi/3) \text{ volt} \).
The power dissipated in the circuit is

  1. A 1.25 W
  2. B 2.50 W
  3. C 3.1250 W
  4. D 4.10 W
Verified Solution

Answer & Solution

Correct Answer

(A) 1.25 W

Step-by-step Solution

Detailed explanation

\( V_0 = 100 \text{ V}, I_0 = 50 \text{ mA} = 0.05 \text{ A}, \phi = \pi/3 \) \( P = \frac{V_0 I_0}{2} \cos(\phi) \) \( P = \frac{100 \times 0.05}{2} \cos(\pi/3) \) \( P = \frac{5}{2} \times \frac{1}{2} = 1.25 \text{ W} \)