JEE Main20209 Jan 2020Evening ShiftPhysicsAlternating CurrentActual
In L C circuit the inductance L = 40 mH and capacitance C = 100 μF . If a voltage V t = 10 s i n 314 t is applied to the circuit, the current in the circuit is given as:
Options
- A0.52 cos ⁡ 314 t
- B10 cos ⁡ 314 t
- C5.2 cos ⁡ 314 t
- D0.52 sin ⁡ 314 t
Correct answer
A. 0.52 cos ⁡ 314 t
Step-by-step solution
z = R 2 + X C - X L 2 R = 0 Z = X C - X L = 1 ω C - ω L = 1 314 × 100 × 10 - 6 - 314 × 40 × 10 - 3 = 31.84 - 12.56 = 19.28   Ω i = V 0 Z sin ⁡ 314 t + π 2 ∴ i = V 0 Z cos ⁡ 314 t ⇒ i = 10 19.28 cos ⁡ 314 t ⇒ i = 0.52 cos ⁡ 314 t