JEE Main202125 Feb 2021Morning ShiftPhysicsAlternating CurrentActual
The angular frequency of alternating current in a L-C-R circuit is 100 rad s - 1 . The components connected are shown in the figure. Find the value of inductance of the coil and capacity of condenser.
Options
- A1 . 33   H and 150   μ F
- B0 . 8   H and 150   μ F
- C1 . 33   H and 250   μ F
- D0 . 8   H and 250   μ F
Correct answer
D. 0 . 8   H and 250   μ F
Step-by-step solution
Current through 60   Ω resistance = 15 60 = 1 4 A thus capacitor current = 1 4   A ∵     V C = I   X C 10 = 1 4 × 1 ω C ∴   C = 1 40 ω = 1 4000 = 250   μ F Now, current through 40   Ω resistance = 20 40 = 1 2   A thus current through inductor = 1 2 - 1 4 = 1 4   A V L = I X L = 1 4 × ω L 20 = 1 4 × 100 × L ⇒ L = 0 . 8   H