Digital Computer Electronics — Part 2 MCQs with Explanations
Practice high-yield Computer Science & IT MCQs on Digital Computer Electronics — Part 2 with worked academic solutions for PPSC, FPSC, CSS, PMS, NTS.
Questions
40
Difficulty Level
Exam-Level
Target Exams
PPSC, FPSC, CSS...
Estimated Time
48 mins
Exam-Level PPSC FPSC CSS PMS NTS
Verified for Commission Syllabus • Oct 14, 2026
40
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Question 1 of 40
★ PPSC
★ FPSC
★ PPSC
★ FPSC
An inverter is also called a _____ gate.
Correct Answer: Option A — NOT
Detailed Academic Explanation:
NOT is the correct answer to “An inverter is also called a _____ gate.”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
Conversion of decimal number 13 10 to it's octal number equivalent is
Correct Answer: Option A — 158
Detailed Academic Explanation:
158 is the correct answer to “Conversion of decimal number 13 10 to it's octal number equivalent is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
1 is the correct answer to “The binary number 1100 0101 has _____ bytes”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
With a NAND latch a low R and a low S produce a _____ condition.
Correct Answer: Option A — race
Detailed Academic Explanation:
race is the correct answer to “With a NAND latch a low R and a low S produce a _____ condition.”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
Which of the following logic families has the highest noise immunity?
Correct Answer: Option D — HTL
Detailed Academic Explanation:
HTL is the correct answer to “Which of the following logic families has the highest noise immunity”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
The ALU carries out arithmetic and logic operations. It processes _____ numbers rather than decimal numbers.
Correct Answer: Option C — binary
Detailed Academic Explanation:
binary is the correct answer to “The ALU carries out arithmetic and logic operations. It processes _____ numbers rather than decimal numbers.”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
Conversion of decimal number 71 10 to it's binary number equivalent is
Correct Answer: Option D — 10001112
Detailed Academic Explanation:
10001112 is the correct answer to “Conversion of decimal number 71 10 to it's binary number equivalent is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
Which of the following flip-flops is free from race around problem?
Correct Answer: Option C — master slave JK flip-flop
Detailed Academic Explanation:
master slave JK flip-flop is the correct answer to “Which of the following flip-flops is free from race around problem”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
Conversion of decimal number 67 10 to it's octal number equivalent is
Correct Answer: Option B — 1038
Detailed Academic Explanation:
1038 is the correct answer to “Conversion of decimal number 67 10 to it's octal number equivalent is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
A NOR gate has two or more input signals. All input must be _____ to get a high output
Correct Answer: Option A — low
Detailed Academic Explanation:
low is the correct answer to “A NOR gate has two or more input signals. All input must be _____ to get a high output”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
If a microcomputer has a 64K memory, what are the hexadecimal notations for the first and last memory location?
Correct Answer: Option C — 0000, FFFF
Detailed Academic Explanation:
0000, FFFF is the correct answer to “If a microcomputer has a 64K memory, what are the hexadecimal notations for the first and last memory location”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
A microprocessor has memory locations from 0000 to 3FFF. Each memory location stores 1 byte. How bytes can the memory store? Express this in kilobytes?
Correct Answer: Option B — 16,384, 16K
Detailed Academic Explanation:
16,384, 16K is the correct answer to “A microprocessor has memory locations from 0000 to 3FFF. Each memory location stores 1 byte. How bytes can the memory store? Express this in kilobytes”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
m full adders is the correct answer to “The m-bit parallel adder consists of:”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
An OR gate has 6 inputs. How many input words are in its truth table?
Correct Answer: Option A — 64
Detailed Academic Explanation:
64 is the correct answer to “An OR gate has 6 inputs. How many input words are in its truth table”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
schottky-clamped TTL is the correct answer to “Which TTL sub-family has maximum speed”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
Conversion of binary number 110001 2 to its decimal number is
Correct Answer: Option B — 4910
Detailed Academic Explanation:
4910 is the correct answer to “Conversion of binary number 110001 2 to its decimal number is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
The OR gate has two or more input signals. If any input is _____ the output is high.
Correct Answer: Option B — high
Detailed Academic Explanation:
high is the correct answer to “The OR gate has two or more input signals. If any input is _____ the output is high.”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
How many memory locations can 14 address bits access?
Correct Answer: Option A — 16,384
Detailed Academic Explanation:
16,384 is the correct answer to “How many memory locations can 14 address bits access”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
All of the above is the correct answer to “The ASCII code is a 7-bit code for”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
The EXCLUSIVE - NOR gate is equivalent to an _____ gate followed by an invertor.
Correct Answer: Option D — XOR
Detailed Academic Explanation:
XOR is the correct answer to “The EXCLUSIVE - NOR gate is equivalent to an _____ gate followed by an invertor.”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
The 2's compliment of binary number 010111.1100 is
Correct Answer: Option B — 101000.01
Detailed Academic Explanation:
101000.01 is the correct answer to “The 2's compliment of binary number 010111.1100 is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
In boolean algebra, the times sign stands for the _____ operation
Correct Answer: Option A — AND
Detailed Academic Explanation:
AND is the correct answer to “In boolean algebra, the times sign stands for the _____ operation”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
What logic function is obtained by adding an inverter to the output of an AND gate?
Correct Answer: Option B — NAND
Detailed Academic Explanation:
NAND is the correct answer to “What logic function is obtained by adding an inverter to the output of an AND gate”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
Conversion of an octal number 7432 8 to a binary number is
Correct Answer: Option B — 1111000110102
Detailed Academic Explanation:
1111000110102 is the correct answer to “Conversion of an octal number 7432 8 to a binary number is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
Conversion of an octal number 143 8 to hexadecimal number is
Correct Answer: Option A — 6316
Detailed Academic Explanation:
6316 is the correct answer to “Conversion of an octal number 143 8 to hexadecimal number is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
The memory cell of a dynamic RAM is simpler and smaller than the memory cell of a _____ RAM.
Correct Answer: Option B — static
Detailed Academic Explanation:
static is the correct answer to “The memory cell of a dynamic RAM is simpler and smaller than the memory cell of a _____ RAM.”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
eight is the correct answer to “A byte is consist of _____ bits”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
What is the 1's complement of 0000 1111 0010 1101 number?
Correct Answer: Option B — 1111 0000 1101 0010
Detailed Academic Explanation:
1111 0000 1101 0010 is the correct answer to “What is the 1's complement of 0000 1111 0010 1101 number”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
101112 is the correct answer to “Addition of 1101 2 and 1010 2 is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
A NAND gate is equivalent to an AND gate followed by an inverter. All inputs must be _____ to get a low output
Correct Answer: Option B — high
Detailed Academic Explanation:
high is the correct answer to “A NAND gate is equivalent to an AND gate followed by an inverter. All inputs must be _____ to get a low output”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
What logic function is produced by adding an inverter to the output of an AND gate?
Correct Answer: Option A — NAND
Detailed Academic Explanation:
NAND is the correct answer to “What logic function is produced by adding an inverter to the output of an AND gate”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
Conversion of decimal number 28 10 to it's octal number equivalent is
Correct Answer: Option C — 348
Detailed Academic Explanation:
348 is the correct answer to “Conversion of decimal number 28 10 to it's octal number equivalent is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
1112 is the correct answer to “Division of 100011 2 by 101 2 is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
The NOR gate is logically equivalent to an OR gate followed by an _____
Correct Answer: Option D — inverter
Detailed Academic Explanation:
inverter is the correct answer to “The NOR gate is logically equivalent to an OR gate followed by an _____”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
Correct Answer: Option D — none of the combinational and sequential circuits
Detailed Academic Explanation:
none of the combinational and sequential circuits is the correct answer to “The dynamic race hazard problem occurs in”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
Resistor Ratio design is used in linear ICs because
Correct Answer: Option C — Precise resistor values are not possible with IC processes
Detailed Academic Explanation:
Precise resistor values are not possible with IC processes is the correct answer to “Resistor Ratio design is used in linear ICs because”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
What advantages do ICs have over discrete-device circuits due to their greater complexity (i.e. more circuitary in less area)
Correct Answer: Option D — All of the above
Detailed Academic Explanation:
All of the above is the correct answer to “What advantages do ICs have over discrete-device circuits due to their greater complexity (i.e. more circuitary in less area)”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
Conversion of an octal number 136 8 to hexadecimal number is
Correct Answer: Option B — 5E16
Detailed Academic Explanation:
5E16 is the correct answer to “Conversion of an octal number 136 8 to hexadecimal number is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
The control and arithmetic-logic sections are called the _____
Correct Answer: Option D — Central Processing Unit
Detailed Academic Explanation:
Central Processing Unit is the correct answer to “The control and arithmetic-logic sections are called the _____”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
How many full adders are required to construct an m- bit parallel adder?
Correct Answer: Option B — m-1
Detailed Academic Explanation:
m-1 is the correct answer to “How many full adders are required to construct an m- bit parallel adder”. This question is standard in competitive examination syllabi for Digital Computer Electronics.
In competitive commission exams (FPSC, PPSC, KPPSC, SPSC, CSS, PMS), questions are frequently phrased with distractor options designed to catch rote learners. Whenever you answer an MCQ, read the Detailed Academic Explanation and Conceptual Anchor to understand why the remaining options are incorrect.