Question

For a series LCR 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.

• A. (a) and (d) only
• B. (b) and (d) only
• C. (a) and (c) only
• D. (b) and (c) only

Answer 1

Answer: (C)

(a) and (c) only

Answer 2

The correct option is(C): (a) and (c) only

We know that

$X_c=\frac{1}{wC}$

and X L = ω L

Also, at ω = ω r : X L = X C

⇒ For ω<ω r : capacitive

and At

$w=w_r:z=\sqrt{R^2+(X_L-X_C)^2}=R$