NEETPhysicsAlternating Current
For a series L C R circuit, I vs ω curve is shown (a) To the left of ω r , the circuit is mainly capacitive. (b) To the left of ω r , the circuit is mainly inductive. (c) At ω r , impedance of the circuit is equal to the resistance of the circuit. (d) At ω r , impedance of the circuit is 0 . Choose the most appropriate answer from the options given below.
Options
- A(a) and (d) only
- B(b) and (d) only
- C(a) and (c) only
- D(b) and (c) only
Correct answer
C. (a) and (c) only
Step-by-step solution
The impedance of an AC circuit is given by, Z = R 2 + X C - X L 2 . For current to be maximum Z should be minimum. The value of Z will be minimum when X C - X L = 0 . Therefore, the value of Z = R . Hence, statement C is correct and statement D is wrong. To the left of ω r i.e. when ω < ω r , X C > X L . Therefore, the circuit is mainly capacitive. Hence, statement A is correct and statement B is wrong.