26. The circuit shown in figure
    

1. 1. is MOD – 2 counter

   
   
   

   2. is MOD – 3 counter

   
   
   

   3. generate sequence 00, 10, 01, 00....

   
   
   

   4. generate sequence 00, 10, 00, 10, 00.....

   
   
   

---

1. View Hint View Answer Discuss in Forum

   
   From table it is clear that it is a MOD – 3 counter.
   

   Correct Option: B

   
   From table it is clear that it is a MOD – 3 counter.
   

---

27. A sequential circuit using D flip-flop and logic gates is shown in the figure where X and Y are the inputs and Z is the output. The circuits is z
    
    

1. 1. S – R FF with inputs X = R and Y = S

   
   
   

   2. S – R FF with inputs X = S and Y = R

   
   
   

   3. J – K FF with inputs X = J and Y = K

   
   
   

   4. J – K FF with inputs X = K and Y = J

   
   
   

---

1. View Hint View Answer Discuss in Forum

   
   Comparing from the truth table of J– K FF
   Y= J, X = K

   Correct Option: D

   
   Comparing from the truth table of J– K FF
   Y= J, X = K

---

---

28. In a 4 bit counter, the outputs of 3 JK FFs from MSB downward are connected to the NAND gate whose output is connected to CLR.

1. 1. It is a MOD-14 counter

   
   
   

   2. It is a MOD-13 counter

   
   
   

   3. It is a divide by-13 counter

   
   
   

   4. It is a divide by-14 counter

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

---

29. The shift register shown in the given figure is initially loaded with the bit pattern 1010. Subsequently the shift register is clocked, and with each clock pulse the pattern gets shifted by one bit position to the right. With each shift, the bit at the serial input is pushed to the left most position (msb). After how may clock pulses will the content of the shift register become 1010 again?
    
    

1. 1. 3

   
   
   

   2. 7

   
   
   

   3. 11

   
   
   

   4. 15

   
   
   

---

1. View Hint View Answer Discuss in Forum

   Y₂ = Q₁ ⊕ Q₀
   Y₁ = Q₂ ⊕ Y₂
   
   The sequences are as follows:
   
   As we see from the table, sequence 1010 repeats after 7 cycles.

   Correct Option: B

   Y₂ = Q₁ ⊕ Q₀
   Y₁ = Q₂ ⊕ Y₂
   
   The sequences are as follows:
   
   As we see from the table, sequence 1010 repeats after 7 cycles.

---

---

30. If a counter having 10 FFs is initially at 0, what count will if hold after 2060 pulses?

1. 1. 000 000 1100

   
   
   

   2. 000 001 1100

   
   
   

   3. 000 001 1000

   
   
   

   4. 000 000 1110

   
   
   

---

1. View Hint View Answer Discuss in Forum

   It completes one cycle 1024 pulses For 2060/1024 = 2048 or 2cycles
   Balance = 2060 – 2048 = 12 pulses
   Binary 12 = 000 000 1100

   Correct Option: A

   It completes one cycle 1024 pulses For 2060/1024 = 2048 or 2cycles
   Balance = 2060 – 2048 = 12 pulses
   Binary 12 = 000 000 1100

---