Q1: An RL low-pass filter consists of a 5.6 mH coil and a 3.3 k resistor. The output voltage is taken across the resistor. The circuit's critical frequency is

ANS:A - 93.8 kHz

No, @SANA.

Critical frequency is the highest magnitude of frequency above which the waves penetrate the ionosphere and below which the waves are reflected back from the ionosphere.

Ionosphere: The layer of the earth's atmosphere which contains a high concentration of ions and free electrons and is able to reflect radio waves.

CUT OFF FREQUENCY: It is a level above or below at which the system fails to operate.