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JEE Main · 2022 · 26 Jun 2022 · Shift 2 · Semiconductors

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The positive feedback is required by an amplifier to act an oscillator. The feedback here means :
  1. (A)External input is necessary to sustain ac signal in output.
  2. (B)A portion of the output power is returned back to the input.✓ Correct
  3. (C)Feedback can be achieved by LR network.
  4. (D)The base-collector junction must be forward biased.

Answer: (B)

Solution

In an oscillator, positive feedback means that a portion of the output signal is fed back to the input in phase, which sustains oscillations without requiring an external input signal. This is the fundamental principle of oscillator operation.

JEE Main · 2022 · 26 Jun 2022 · Shift 2 · Single correct option

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