Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main202226 Jun 2022Evening ShiftPhysicsSemiconductorsActual

The positive feedback is required by an amplifier to act as an oscillator. The feedback here means

Options

  1. AExternal input is necessary to sustain ac signal in output.
  2. BA portion of the output power is returned back to the input.
  3. CFeedback can be achieved by LR network.
  4. DThe base-collector junction must be forward biased.

Correct answer

B. A portion of the output power is returned back to the input.

Step-by-step solution

When the amplifier connects with positive feedback, it acts as the oscillator. The feedback employed here is positive feedback, this means some amount of the output voltage is given to the input. Hence, the circuit continues its process without any input to the oscillator. The positive feedback is also known as regenerative feedback because the system sustains or regenerates itself without any input source. Hence, the oscillator is nothing but an amplifier with the positive feedback.

Practice Semiconductors on Quantrex Academy →

More from Semiconductors

The output Y for the given inputs A and B to the circuit is: 2026Refer to the logic circuit given below. For two inputs (A=1, B=1) and (A=0, B=1) , output (Y) will be __________. 2026The maximum rated power of the LED is 2 mW and it is used in the circuit with input voltage of 5 V as shown in the figure below. The current through resistance R_S is 0.5 mA. The m 2026In a semiconductor p-n diode, the doping concentrations on p-side and n-side are 10¹⁵ atoms/cm ^3 and 10¹⁸ atoms/cm ^3 , respectively. Which one of the following statements is true 2026For the given logic circuit, which of the following inputs combination will make both LED -1 and LED -2 to glow? 2026Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A: A diode under reverse-biased condition provides very small current 2026A diode has Zener voltage of 10 V and maximum power dissipation of 0.5 W, then the minimum resistance to be used in series with this diode for safety when it is connected to a 25 V 2026Two 4 bits binary numbers, A = 1101 and B = 1010 are given in the inputs of a logic circuit shown in figure below. The output (Y) will be: 2026 Full Semiconductors list All JEE Main PYQs