Theoritical Question related to BCA101 Digital Electronics for 1st Semester Students.

The ones who have been applying for 1st semester WBUT BCA101 might want to look over this and keep everything posted here noted! this will be the theoretical aspects of the question asked over and over again and might work the trick to getting you win “marks”. I personally do not believe in grades, a man is as good as his sword and his sword is as good as his arms!

  • State and mention the main differences between sequential and combinational circuits.
  • Define Flip flops, and it’s propagation delay.
  • What is a decoder?
  • what are shift registers?
  • what is a PROM?
  • what are priority checkers?
  • what is a ring counter?
  • what is the full subtractor?
  • explain the differences between the ring counter and the Johnson counter with proper state and circuit diagram.
  • Explain the concept of Parity checking
  • Discuss about the design of an odd parity and even parity generator.
  • What is biased exponent in relation to floating point representation? (FPR)?
  • What do you mean by race conditions in a flip flop? Design a JK-flip flop and discuss about it’s operation.
  • What are the universal gates?
  • Draw a block diagram of a digital Microprocessor and explain it’s functions.
  • What do you mean by a sequential circuit?
  • What are the synchronous and asynchronous sequential circuits?
  • Explain the functionality of D-Flip Flop. Give the truth table and state the diagrams.
  • What do you mean by edge triggering level and level triggering in flip flops?
  • What is a flip flop?
  • What are the uses of a flip flop?
  • Give the circuit diagram of a JK-Flip Flop
  • Give the truth tables of SR and JK flip flops
  • Write a short note on excitation table
  • Write a short note on ripple counters
  • Explain the differences between a RAM and a ROM
  • Write a short note on parity checking
  • Write a short note on ring counter
  • Write a short note on magnitude comparator.

These are the question which are frequently asked and compiled here for easy references. I hope this finds you or you find this in a good ay and start off working on the same. Also, try other sections to take out most of my posts! will be catching you people soon! Roger out!./-

Digital Electronics and topics for considerations.

Here are some compiled topics after some basic analysis, which have been conformed to hit on the examinations year each and roll back again to the coming years. The content remains the same, pattern seldom changes, so a minor trick could do it all. I have chalked out all the topics I am aware of in this post and I am not responsible if these doesn’t hit. But as per my experiences on the internals as well as the externals, and after going through each question papers from the last 4 years that is from 2009 until 2013, this is what the whole Digital Electronics for 1sst semester BCA is composed of and of course which get’s entry to the exams!

A brief Syllabus is:

1.) Data and Number Representation.
2.) Binary Complement Representation *(BCD-ASCII)
3.) Conversion of one number system to another (conversions!)
4.) 2’s complement Representation.
5.) Binary Arithmetic.
6.) Logic Gates.
7.) Basic Logic Operations.
8.) Truth Tables.
9.) Boolean Expressions.
10.) Simplification of Expressions.
11.) Computational Circuits.
12.) Adders and Subtractors.
13.) Multiplexers.
14.) Encoders and Decoders.
15.) Sequential Circuits.
16.) Flip Flops.
17.) Registers.
18.) Counters (Asynchronous and Synchronous)
19.) Memory Circuits.
20.) ROM, PROM, EPROM, and DRAM (Memory devices!)

Now, something has to be said here, the analysis and deduction of topics I am going to post over here, 90% of them went hit to the exams on 2014; now this might help you and the trick is not to forget these topics after the exams, because the same applies to ‘Computer Architecture’ when you go in the 2nd semester and binary conversions and certain arithmetic operations are required to move ahead. I say, DO NOT ever forget these topics in your whole life if you are really serious about enjoying the computers. It’s just a game and the memory devices are too much fun playing with. If you notice, I have here a penetration testing section as well, this follows RE (Reverse Engineering), which of-course is out of scope of the discussion here and the topic itself is vast and kept away from general academic overview, but these will be THE REAL topics you might had ever confronted to start the basics off.

Now to the analysis of the topics I had compiled (remember, I passed out 1st semester and therefore I  am keeping this minimal as this blog wasn’t created before the 1st semester and indeed, you could find more resources from the 2nd semester onwards!)  .. I keep this neat and clean and onto the topic. There would be questions answered via the PM (email me! at or drop comments here directly! I will be also deducting some of the necessary question for DE for 1st semester here as well.

What I have compiled here are from my own perspective and a clear analysis of measures I took to complete the DE syllabus entirely in a perfect way with a perfect sense. Now if this analysis does not help you or you don’t understand it, leave it here, grab the general book which every general students does and restrict yourselves to it. It’s my way of doing things here…

Analysis of topics from BCA101 (WBUT enroll’d), 2008, 2009, 2010, 2011, and 2012 papers:

1.) De-Morgan’s theorem.
2.) 1’s complement and 2’s complement.
3.) Encoders.
4.) Decoders.
5.) Parity Generators

  • Odd Parity Generators
  • Even Parity Genarators
  • Parity Checkers and Parity Checking

6.) Gray Code

  • Gray-Binary convertor and conversion

7.) BCD (Binary Coded Decimal)

  • Excess-3 Code

8.) Multiplexers.
9.) Adders

  • Full Adders
  • Half Adders

10.) Subtractors

  • Full Subtractors
  • Half Subtractors

11.) Even Parity Hamming Code.
12.) K-Maps.
13.) Positional Number System.
14.) Sequential Circuits

  • Synchronous Sequential Circuits.
  • Asynchronous Sequential Circuits.

15.) Deduction of NAND to all the other Logic gates which exists, NOR, XOR, OR, AND, NOT etc.. (BUFFER is not needed!)
16.) XOR via NAND using 4×2 Input NAND.
17.) Differences between Sequential and Combinational Circuits.
18.) Shift Registers.
19.) Flip Flops

  • J-K flip flops.
  • S-R Flip flops.

20.) Counters

  • Synchronous Counters
  • Jonson Counters/Ring Counters, 4-bit Ring Counters as part of Synchronous counters

21.) Priority Checkers
22.) PROM
23.) Floating point Representation

Now the extras are which would and are likely to appear are as follows:

  • Parity Generators
  • Parity Checkers
  • What is Race Condition?
  • 4×1 Multiplexers
  • Design a full Subtractor with 4×1 Multiplexers
  • Advantage of JK-flip flops over Sr flip flops
  • Differences between combinational and sequential circuits.
  • Conversion of JK-flip flops to D flip flops
  • Conversion of D flip flops to JK-Flip flops

Test Analysis deduction of possible necessary in-evitable topics!

  • Parity generators
  • Parity checkers and parity checking
  • BCD
  • BCD Excess 3 code
  • Full adders and Half adders
  • Full subtractors and half subtractors
  • K-Maps
  • Sequential Circuits
  • JK flip flops
  • Sr flip flops
  • Counters (all counters!) specially ring and Johnson ones for 4-bit!
  • Shift Registers
  • Fractional Octal Numbers
  • Fractional Octal number conversions
  • Sum of Products (SOP)
  • POS (Product of Sums)
  • Gray-Binary Convertor and conversion (2-bit)
  • Bias Exponent and FPR (Floating point Representation)
  • Race conditions in Flip Flops
  • Flip Flop Excitation Tables.

If you don’t follow up and get confused, as stated mail me and I’ll be happy to help you there. Please do not ask for the resources, as I seem to have lost them in an accident, refer to post to know about it! this is totally from scratch I am making this over and I am past the 1st semester. For the sake of keeping all alive and sharing, I am offering this. Do not take this as your advantage. Roger out!./-

1st Semester shares, resources, posts and Syllabus WBUT.

I will quickly add this up. Now, since I am enrolled to an academic university (WBUT), India before i created this blog; I have to keep this academic centric and hence you won’t find much on 1st semester category. The 1st semester went out and soon after this 1st semester, I had taken up this blog and therefore all the posts you find here might be minimal… I will keep adding things here but cannot guarantee you the whole out of it. I might point out resources tho.

What we have here on this 1st post are the subjects for BCA and an overview.

1.) Digital Electronics.
2.) Mathematics.
3.) Introduction to Programming.
4.) PC-Software
5.) Business System and Application.

Please see the appropriate sections under the ‘1st Semester’ category to get a lead onto these subjects. Entries would be updated once I am free to post them here.