# Questions on Sequential Circuits

Jan 12 • Resources • 21296 Views • 15 Comments on Questions on Sequential Circuits

Q.1. What is sequential circuit?
Ans. These are defined as digital circuit whose output is dependent not only on the present input value but also on the past history of its input. The sequential Circuits are designed using the combinational circuits along with a memory devices known as Flip-Flops. The sequential Circuits depend over the input value as well as the stored levels.

Sequential Circuits block diagram

Q.2. What is a flip flop?
Ans. Flip flop is one bit storage bistable device. Flip flop is also called latch. It stores binary value. It is the basic building block of the digital electronic systems. These are the basically the data storing devices which store the information of two stable states of the system. A flip-flop stores only a single bit of data at a time.

Q.3. What is the difference between latch and flip flop?
Ans. The difference between the latch and flip flop is the method of changing their state. The latch do not have clock input but flip flop has a clock input.

Latch Vs Flip Flop

Q.4. Does sequential circuit contain memory element?
Ans. Yes, sequential circuit contain memory element. A storing element is added to store the various stable state levels information. This help in relating the feedback data from the past to the present data.

Q.5. What is the application of T flip flop?
Ans. T Flip Flops can be used as follows-

(a) Frequency divider
(b) Counters

Q.6. How race around condition can be eliminated?
Ans. It is essential to understand the race around condition before the development of edge triggered flip flop. As we know that the conditions s==1 and R==1 are not allowed in flip flop by the use of feedback correction. Under this situation when input J and K are 1 and 1 output will change from 0 to 1. To avoid race around condition,we use master slave flip flop. It has two different flip flop, which are connected serially.

Q.7. What is a counter?
Ans. Counter is a sequential circuit which is  used to count the number of clock pulses of the circuit. It is also sometimes used to display the number of time any event is repeated or happening. It’s a simple counter in the digital logics and computation which calculates the number of times an assigned event is taking place.

Q.8. What is the difference between asynchronous counter and synchronous counter ?
Ans. Asynchronous counter’s speed is less while synchronous counter’s speed is high. In asynchronous glitch occurs while in synchronous, there is no problem of glitch. In asynchronous settling time is more while in synchronous settling time is less. Asynchronous counters are simple and straight in operation while synchronous are complex in operation.

Q.9. How many types of shift register counters are there and write their names also?
Ans. There are two types of shift register counters which are named as-

(a) Ring counter and
(b) Johnson counter.

Q.10. What is a register?
Ans. Register is a group of flip flop or binary cells which holds the binary information. Since a binary cell store a bit of information, n bit register has n flip flops and is capable of storing any information of n bit.

### 15 Responses to Questions on Sequential Circuits

exercise on sequential circuit

exercise on sequential circuit

3. Male Wasswa Enock says:

The master JK flip flop

4. Male Wasswa Enock says:

The master JK flip flop

5. Male Wasswa Enock says:
6. Brightone says:

2.A synchronous counter uses JK flip flops and goes through the following repeated
Sequence: 1,3, 5, 7…
a.Construct the state transition diagram for the circuit. [2]
b.Construct the state table (present state-next state table) for the circuit. [6]
c.Design the synchronous circuit. [10]

7. Anonymous says:
8. Anonymous says:
9. Anonymous says:
10. Ekunkan Damilare says:

I don’t know how to write the VHDL code in any sequential circuit or counters

11. Hardik Sanghvi says:

difference between sequential and combinational circuit

12. Ritika says:

Basic questions that are meant to clear fundamentals of electronics engineers, vitally important for interviews.

13. sakshi chaudhary says:

Above Post on sequential circuits is really useful as sequential circuits are the building block of the Digital Electronics and are somewhat complicated to understand and with the help of this post we can easily grasp the basics concepts and uses of it…!!!!!!!

14. Saurabh Singh says:

A very good post with nice explanation about sequential circuits nad deviices used in it..must have a look

15. Siddhant Tripathi says:

Sequential circuits are mostly used in the digital circuitry of complex networks and devices.
A good discussion over the topic.