Question

At very high frequencies, the effective impedance of the given circuit will be ________ \(\Omega \).



10 O05F 20 OS5F I AMW— | AMW— J—D.SF 10 20H 20 OS5F 220V

• A. 2.0
• B. 2
• C. 2.00

Answer 1

Answer: (A), (B), (C)

We know that,

Inductive reactance is $X_L=2\pi fL$
Capacitative reactance is $X_C=\frac{1}{2\pi fC}$
At large frequencies inductor acts as open circuit $\left(X_L\text{is very large}\right)$ and capacitor as short circuit $\left(X_C\text{is very small}\right)$

Hence circuit can be reduced as


Here Resisatnce $1\Omega$ is in series with combination of two $2\Omega$ resistances in parallel.
Hence, Effective impedance is $1+\frac{2\times 2}{2+2}=2\Omega$