211. Find the odd one out:

1. 1. Sweep voltage generators

   
   
   

   2. Multi vibrators

   
   
   

   3. Sine wave oscillators

   
   
   

   4. Blocking oscillators

   
   
   

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   NA

   Correct Option: C

   NA

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212. For oscillations to start, the loop gain AB of the oscillator must be initially:

1. 1. less than unity

   
   
   

   2. 0.5

   
   
   

   3. 1.0

   
   
   

   4. more than unity.

   
   
   

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   NA

   Correct Option: D

   NA

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213. In a Hartley oscillator the condition for sustained oscillations is
     h_fe = L₁ L₂.
     If there exists mutual inductance M between coils L₁ and L₂, then the above condition will get modified as h_fe

1. 1. ML1

      L2

   
   
   

   2. L1

      ML2

   
   
   

   3. L1 + M

      L2 + M

   
   
   

   4. L1 – M

      L2 – M

   
   
   

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   NA

   Correct Option: B

   NA

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214. In regard to Wien bridge oscillator:

1. 1. the bridge is unbalanced so that the amplitude of oscillations can be stable

   
   
   

   2. at the frequency of oscillations the bridge is exactly balanced

   
   
   

   3. in the bridge arms containing only resistors, one of the resistors is temperature sensitive to stable the amplitude of oscillations

   
   
   

   4. at the frequency of oscillations the gain is exactly 3

   
   
   

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   NA

   Correct Option: C

   NA

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215. In regard to various types of oscillators:

1. 1. LC oscillators are more stable than crystal oscillators

   
   
   

   2. Crystal oscillators have highest Q

   
   
   

   3. Phase-shift oscillator have the widest range of frequency

   
   
   

   4. Wien bridge oscillator is used where a single frequency oscillator is required

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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