Two Marks Questions with Answers

Two Marks Questions with Answers

 

Q.1 Define registers.

Ans. : A register is a group of flip-flops. So an n-bit register has a group of n flip-flops and is capable of storing any binary information/number containing n-bits.

 

Q.2 Define shift registers.

Ans. : The binary information in a register can be moved from stage to stage within the register or into or out of the register upon application of clock pulses. This type of bit movement or shifting is essential for certain arithmetic and logic operations used in microprocessors. This gives rise to group of registers called shift registers.

 

Q.3 What are the different types of shift type ?

OR

Classify the registers with respect to serial and parallel input output.

There are five types. They are,

• Serial In Serial Out Shift Register

• Serial In Parallel Out Shift Register

• Parallel In Serial Out Shift Register

• Parallel In Parallel Out Shift Register

• Bidirectional Shift Register

 

Q. 4 What is the difference between serial and parallel transfer? What type of register is used in each case?

Ans. : When data is transferred one bit at a time, the process of transfer is known as serial transfer. When multiple bits of data are transferred at a time, the process is known as parallel transfer. For parallel transfer, we can use parallel in and parallel out register. For serial transfer we can use left shift or right shift register.

 

Q. 5 If a serial-in-serial-out shift register has N stages and if the clock frequency is f, what will be time delay between input and output ?

AU : Dec.-03

Ans. : The time delay between input and output

is T_D = N / f

 

Q.6 Draw the timing diagram of 4-bit ring counter.

AU : Dec.-04

Ans. :

 

Q.7 Draw a 2-bit ripple counter and convert this into a 2-bit ring counter.

(Refer section 6.6)

 

Q.8 Define universal shift register.

Ans. : The register which has both shifts (right-shift and left-shift) and parallel load capabilities is referred to as universal shift register.

 

Q.9 Mention applications of shift registers.

Ans. :

1. Delay line

2. Serial to parallel converter

3. Parallel to serial converter.

4. Pseudo-random binary sequence generator.

5. Sequence detector.

 

Q.10 What is shift register counter ?

Ans. : A shift register can also be used as a counter. A shift register with the serial output connected back to the serial input is called shift register counter.

 

Q.11 What are the advantages of shift registers ? (Refer section 6.5)

Q.12 What are the applications of a shift register ? (Refer answer of Q.9)

 

Q.13 How many flip-flops are needed to build an 8-bit shift register ?

AU : Dec.-02, CSE

Ans. :          8 flip-flops are needed to build an 8-bit shift register.

 

Q.14 A shift register comprises of JK flip-flops. How will you complement the contents of the register ?

AU : May-03, CSE

Ans. : In shift registers outputs J and K of previous flip-flop is connected to the inputs of the next flip-flop. If these lines are connected through OR as shown in Fig. 6.2, we can complement the contents of flip-flop. When complement line is high all J and K inputs will be high and flip-flops will complement the output.

 

Q.15 What is a shift register ? (Refer answer of Q.2)

AU : Dec.-03, CSE

 

Q.16 How many states are there in a 3-bit ring counter? What are they ?

AU : May-07, CSE/IT

Ans. : Three - 001, 010, 100.

 

Q.17 What is shift register ? List the types.

(Refer answer of Q.2 and Q.3)

AU : May-09, CSE/IT

 

Q.18 What is ring counter ? AU : Dec.-12

Ans. : A ring counter is a type of counter composed of a type circular shift register. The output of the last shift register is fed to the input of the first register.

 

Q.19 What is twisted ring counter ?

Ans. : A twisted ring counter, also called Johnson counter connects the complement of the output of the last shift register to the input of the first register and circulates a stream of ones followed by zeros around the ring.