Identify the circuit.

Question

Question

This question was previously asked in

URSC (ISRO) Technician B (Electronic Mechanic): Previous Year Paper (Held on 20 Nov 2016)

Answer 1

Given circuit has an inductor with inductance value 1 mH and a resistor with 100 kΩ, the output is taken across the resistor.

Hence the according to voltage division the output voltage:

\({V_o} = \frac{{{V_{in}}{X_R}}}{{{X_R} + {X_L}}}\)

Here X_R = 100 kΩ

X_L = jωL = jω × 10^-3 Ω

For small values of frequency (ω) the values of X_Lis very small compared to X_R hence the V_ois equal to V_in.
At very high frequencies the value of X_L will be far greater than X_R hence V_o will tend towards zero.

Hence the circuit acts as a low pass filter which allows AC signals at low frequencies and blocks very high-frequency signals.