201. RC oscillator can be used up to:
     

1. 1. 1 kHz

   
   
   

   2. 10 kHz

   
   
   

   3. 50 kHz

   
   
   

   4. 100 kHz

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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202. If 1.5% of the output of an amplifier is feedback negatively to the input, the minimum gain required of the amplifier for oscillations to occur, in the case of phase shift oscillator:

1. 1. 16.6

   
   
   

   2. 44.4

   
   
   

   3. 66.6

   
   
   

   4. 75

   
   
   

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1. View Hint View Answer Discuss in Forum

   The minimum gain required in the phase shift oscillator is 44.5
   If feedback with feedback factor, β = 1.50% = 0.015 is occurred it reduces the gain by factor (1 + Aβ). So in order to make the oscillator
   New gain should be
   A′ = 44.5 (1 + Aβ)
   = 44.5 (1 + 44.5 × 0.015)
   = 74.43
   = 75
   Hence alternative (D) is the correct choice.

   Correct Option: D

   The minimum gain required in the phase shift oscillator is 44.5
   If feedback with feedback factor, β = 1.50% = 0.015 is occurred it reduces the gain by factor (1 + Aβ). So in order to make the oscillator
   New gain should be
   A′ = 44.5 (1 + Aβ)
   = 44.5 (1 + 44.5 × 0.015)
   = 74.43
   = 75
   Hence alternative (D) is the correct choice.

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203. According to Barkhausen criterion in order to sustain the oscillations:

1. 1. loop gain of the circuit must be negligible

   
   
   

   2. loop gain of the circuit must be equal to unity

   
   
   

   3. the phase shift around the circuit must be 180º

   
   
   

   4. None of the above

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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204. A sinusoidal oscillator consists of an amplifier and a:

1. 1. phase shifting network

   
   
   

   2. gate

   
   
   

   3. forward bias

   
   
   

   4. Non-resistive load

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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205. Which of the following oscillator uses a tapped capacitor in the tuned circuit?

1. 1. Multivibrator

   
   
   

   2. Armstrong oscillator

   
   
   

   3. Hartley oscillator

   
   
   

   4. Colpitts oscillator

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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