Case Study Based MCQs on Alternating Current | Class XII Physics
Read the passage given below and answer the following questions from i) to v)
An LC circuit also called a resonant circuit, tank circuit or a tuned circuit is an electric circuit consisting of an inductor represented by the letter L and capacitor, represented by the letter C connected together. An LC circuit is an idealised model since it assumes there is no dissipation of energy due to resistance.
An LC circuit contains a 20 mH inductor and a 50 µF capacitor with an initial charge of 10 mC. The resistance of the circuit is negligible. Let the instant the circuit is closed be t=0.
i) The total energy stored initially is
a) 5 J
b) 3 J
c) 10 J
d) 1 J
ii) The natural frequency of the circuit is
a) 159.24 Hz
b) 200.12 Hz
c) 110.25 Hz
d) 95 Hz
iii) At what time is the energy stored completely electrical?
a) T, 5T, 9T
b) T/2, 5T/2, 9T/2
c) 0, T, 2T, 3T
d) 0, T/2, T, 3T/2
iv) At what time is the energy stored completely magnetic?
a) T/2, 3T/2, T/4
b) T/3, T/9, T/12
c) 0, 2T, 3T
d) T/4, 3T/4, 5T/4
v) The value of XL is
a) 20 Ω
b) 40 Ω
c) 60 Ω
d) 50 Ω
