Digital Circuits Questions and Answers – BCD Adder

This set of Digital Electronics/Circuits Multiple Choice Questions & Answers (MCQs) focuses on “BCD Adder”.

1. The decimal number system represents the decimal number in the form of ____________
a) Hexadecimal
b) Binary coded
c) Octal
d) Decimal
View Answer

Answer: b
Explanation: Binary-coded decimal (BCD) is a class of binary encodings of decimal numbers where each decimal digit is represented by a fixed number of bits, usually four or eight. Hexadecimal and Octal are number systems having base 16 and 8 respectively.

2. 29 input circuit will have total of ____________
a) 32 entries
b) 128 entries
c) 256 entries
d) 512 entries
View Answer

Answer: d
Explanation: 29 input circuit would have 512(2*2*2*2*2*2*2*2*2 = 512) entries.

3. BCD adder can be constructed with 3 IC packages each of ____________
a) 2 bits
b) 3 bits
c) 4 bits
d) 5 bits
View Answer

Answer: c
Explanation: Binary-coded decimal (BCD) is a class of binary encodings of decimal numbers where each decimal digit is represented by a fixed number of bits, usually four or eight. BCD adder can be constructed with 3 IC packages. Each of 4-bit adders is an MSI(Medium scale Integration) function and 3 gates for the correction logic need one SSI (Small Scale Integration) package.
advertisement
advertisement

4. The output sum of two decimal digits can be represented in ____________
a) Gray Code
b) Excess-3
c) BCD
d) Hexadecimal
View Answer

Answer: c
Explanation: The output sum of two decimal digits can be represented in BCD(Binary-coded decimal). Binary-coded decimal (BCD) is a class of binary encodings of decimal numbers where each decimal digit is represented by a fixed number of bits, usually four or eight.

5. The addition of two decimal digits in BCD can be done through ____________
a) BCD adder
b) Full adder
c) Ripple carry adder
d) Carry look ahead
View Answer

Answer: a
Explanation: The addition of two decimal digits in BCD can be done through BCD adder. Every input inserted, in addition by the user converted into binary and then proceed for the addition. Whereas, Full Adder, Ripple Carry Adder and Carry Look Adder are for the addition of binary bits.
Note: Join free Sanfoundry classes at Telegram or Youtube

6. 3 bits full adder contains ____________
a) 3 combinational inputs
b) 4 combinational inputs
c) 6 combinational inputs
d) 8 combinational inputs
View Answer

Answer: d
Explanation: 3 bits full adder contains 23 = 8 combinational inputs.

7. The simplified expression of full adder carry is ____________
a) c = xy+xz+yz
b) c = xy+xz
c) c = xy+yz
d) c = x+y+z
View Answer

Answer: a
Explanation: A full adder is a combinational circuit having 3 inputs and 2 outputs, namely SUM and CARRY. The simplified expression of full adder carry is c = xy+xz+yz.
advertisement

8. Complement of F’ gives back __________
a) F’
b) F
c) FF
d) FF’
View Answer

Answer: b
Explanation: Complement means inversion. So, complement of F’ gives back F, as per the Law of Involution.

9. Decimal digit in BCD can be represented by ____________
a) 1 input line
b) 2 input lines
c) 3 input lines
d) 4 input lines
View Answer

Answer: d
Explanation: Binary-coded decimal (BCD) is a class of binary encodings of decimal numbers where each decimal digit is represented by a fixed number of bits, usually four or eight. Decimal digit in BCD can be represented by 4 input lines. Since it is constructed with 4-bits.
advertisement

10. The number of logic gates and the way of their interconnections can be classified as ____________
a) Logical network
b) System network
c) Circuit network
d) Gate network
View Answer

Answer: a
Explanation: The number of different levels of logic gates is represented in a fashion which is known as a logical network.

Sanfoundry Global Education & Learning Series – Digital Circuits.

To practice all areas of Digital Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]

advertisement
advertisement
Subscribe to our Newsletters (Subject-wise). Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!

Youtube | Telegram | LinkedIn | Instagram | Facebook | Twitter | Pinterest
Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

Subscribe to his free Masterclasses at Youtube & discussions at Telegram SanfoundryClasses.