131. The number of unused states in a 4-bit Johnson counter is—
     

1. 1. 2
      

   
   
   

   2. 4
      

   
   
   

   3. 8
      

   
   
   

   4. 12

   
   
   

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   NA

   Correct Option: C

   NA

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132. How many flip-flops are needed for MOD-16 ring counter and MOD-16 Johnson counter?
     

1. 1. 16, 16
      

   
   
   

   2. 16, 8
      

   
   
   

   3. 4, 8
      

   
   
   

   4. 8, 16

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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133. For the ring oscillator shown the propagation delay of each inverter is 125 pico sec. What is the fundamental frequency of oscillator output?
     
     
     
     

1. 1. 10 MHz
      

   
   
   

   2. 100 MHz
      

   
   
   

   3. 1 GHz
      

   
   
   

   4. 2 GHz

   
   
   

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1. View Hint View Answer Discuss in Forum

   Total propagation delay of the ring oscillator = 4 × 125 ns = 500 ps
   Fundamental frequency,
   

   f =	1	=	1	= 2 GHz
   	tpd		200 PS

   
   

   Correct Option: D

   Total propagation delay of the ring oscillator = 4 × 125 ns = 500 ps
   Fundamental frequency,
   

   f =	1	=	1	= 2 GHz
   	tpd		200 PS

   
   

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134. A 0 to 6 count consists of 3 flip-flops and a combination circuit of 2 input gate. The combination consists of—
     

1. 1. One AND gate
      

   
   
   

   2. One OR gate
      

   
   
   

   3. One AND gate and one OR gate
      

   
   
   

   4. Two AND gates

   
   
   

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   Alternative (A) is the most appropriate choice.
   

   Correct Option: A

   Alternative (A) is the most appropriate choice.
   

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135. Assume that counter is holding the count 0101. What will be the count after 27 clock pulses?
     

1. 1. 0101
      

   
   
   

   2. 0001
      

   
   
   

   3. 1111
      

   
   
   

   4. 0000

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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