Three identical single tuned amplifiers are connected in

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Three identical single tuned amplifiers are connected in cascade. The 3 dB bandwidth of each amplifier is 100 kHz. The overall 3 dB bandwidth will be approximately:

1. 300 kHz
2. 100 kHz
3. 50 kHz
4. 33 kHz

Correct Option: C

Given n = 3
f_H = 100 kHz
f_H^* = 3 dB
bandwidth of 3-cascaded stage and is given by the relation
f_H^* = f_H √2² – 1 kHz
= 100 √2³ – 1 kHz
= 100 √1.2570 – 1 kHz
≈ 100 × .5 kHz
≈ 50 kHz