Explore topic-wise MCQs in Computer Science.

This section includes 135 Mcqs, each offering curated multiple-choice questions to sharpen your Computer Science knowledge and support exam preparation. Choose a topic below to get started.

1.

In which of the following gates, the output is 1, if and only if at least one input is 1?

A. AND
B. NOR
C. NAND
D. OR
Answer» E.
2.

If A ⊕ B = C, then

A. B ⊕ C = A
B. A ⊕ C = B
C. All of these
D. A ⊕ B ⊕ C = 0
Answer» B. A ⊕ C = B
3.

An AND circuit

A. gives an output when all input signals are present simultaneously
B. is a memory circuit
C. is a linear circuit
D. is a -ve OR gate
Answer» B. is a memory circuit
4.

A switching function is symmetric with respect to a set of literals if and only if the function remains unchanged after

A. Any permutation of the literals
B. Two of these literals are interchanged
C. All the literals are changed in clockwise order
D. All the literals are changed in anticlockwise order
Answer» B. Two of these literals are interchanged
5.

If at some instance prior to the occurrence of the clock edge P, Q and R have a value 0 1 and 0 respectively what shall be the value of PQR after the clock edge 

A. 000
B. 001
C. 010
D. 011
Answer» E.
6.

If all the flip -flops were reset to 0 at power on what is the total number of distinct outputs (states )

represented by PQR generated by the counter 

A. 3
B. 4
C. 5
D. 6
Answer» C. 5
7.

The minimum number of D flip -flops needed design and a mod -258 counter is 

A. 9
B. 8
C. 512
D. 258
Answer» B. 8
8.

What is the minimum number of gates required to implement the Boolean function (AB)+C)if we have to use only 2 -input NOR gates 

A. 2
B. 3
C. 4
D. 5
Answer» E.
9.

(1217)8 is equivalent to 

A. (1217) 16
B. (028F) 16
C. (2297) 10
D. (0B17) 16
Answer» C. (2297) 10
10.

Suppose only one multiplexer and one inverter are allowed to be used to implement any boolean function of n variables What is the minimum size of the multiplexer needed 

A. 2 n line to 1 line
B. 2 n +1 line to1 line
C. 2 n -1 line to 1 line
D. 2 n -1 line to 1 line
Answer» D. 2 n -1 line to 1 line
11.

What is the maximum number of different Bool- ean functions involving n Boolean variables 

A. n 2
B. 2 n
C. 2 2 n
D. 2 n 2
Answer» D. 2 n 2
12.

Consider the regular language L=(111 +1111)* The minimum number of states in any DFA accepting this languages is 

A. 3
B. 5
C. 8
D. 9
Answer» E.
13.

A decimal number has 30 digits Approximately how many digits would the binary representation have 

A. 30
B. 60
C. 90
D. 120
Answer» D. 120
14.

A computer with a 32 -bit word size uses 2 s complement to represent numbers the range of integers that can be represented by this computer is 

A. -2 32 to 2 32
B. -2 32 to 2 31
C. -2 31 to 2 31 -1
D. -2 32 to 2 31
Answer» D. -2 32 to 2 31
15.

Which of the following is the binary representation of the hexadecimal number 3 B7F 

A. 0100100111101101
B. 0110001110111100
C. 0011101101111111
D. 0010010000001010
Answer» C. 0011101101111111
16.

Which of the following binary numder is the same as its 2  s complement 

A. 1010
B. 1001
C. No such number exists
D. None of these
Answer» D. None of these
17.

The hexadecimal number A 23 F is represented in binay by 7 is 

A. 1010001000111110
B. 1010010000111111
C. 1010001000111111
D. 11111001100101010
Answer» D. 11111001100101010
18.

What is the binary equivalent of gray code 11100

A. 01011
B. 10101
C. 00111
D. 10111
Answer» E.
19.

If negative numbers are stored in 2 s complement form then range of number that can be stored in 8 bits is 

A. -127 to +127
B. -127 to +128
C. -128 to +127
D. -128 to +128
Answer» D. -128 to +128
20.

If(x 567)8+ (12yx 5)8 =(71yx)8 then values of x and y are   

A. 4, 4
B. 3, 3
C. 4, 3
D. 4, 5
Answer» D. 4, 5
21.

What is the equivalent of (101100111000111100000) 2 n base 32

A. 1192331
B. 2214716
C. 119716
D. 11142316
Answer» C. 119716
22.

Consider a number system with readix 20 The excess code that is necessary or its equivalent binary coded representation is 

A. 7
B. 6
C. 5
D. 4
Answer» E.
23.

Which of the following statements is not true about BCD code 

A. conversion to and from the decimal system can be done easily
B. It is a 8-4-2-1 weighted code
C. (12345678) 10 need 4 bytes in BCD repesentation
D. Complement of a number can be found efficiently
Answer» E.
24.

What is the 2 s complement represntation of -5/8

A. 0.1010
B. 1.0010
C. -0.1101
D. 1.0110
Answer» E.
25.

How many 1 s are present in the binary representation of 15 X256+5 X16 +3 is 

A. 8
B. 9
C. 10
D. 11
Answer» B. 9
26.

The excess 3 code is also called 

A. cyclic reundancy code
B. weighted code
C. self complimenting code
D. algebraic code
Answer» C. self complimenting code
27.

If 12 A7C16 =x8 then value of  x is 

A. 224174
B. 425174
C. 6173
D. 225714
Answer» B. 425174
28.

The sign magnitude representative of decimal number -637 is 

A. 0687
B. 9687
C. 1687
D. 1312
Answer» C. 1687
29.

The sign magnitude representation of binary 1101.011is 

A. 01101.100
B. 10010.100
C. 11101.001
D. 10010.101
Answer» D. 10010.101
30.

The 2 s complements of  binary number 010111.1100is 

A. 101001 .1100
B. 101000.0100
C. 010111 .0011
D. 101000.0011
Answer» C. 010111 .0011
31.

The 1 s complements of the binary number 

A. 1101101 is
B. 00100010
C. 0010011
D. 1101110
Answer» C. 0010011
32.

The result of the subtraction FD 16 -8816 is 

A. 75 16
B. 65 16
C. 5E 16
D. 10 16
Answer» B. 65 16
33.

The result of the addition A0 16 +6B16 is 

A. 10 B16
B. 16 B16
C. AOB 16
D. A6B16
Answer» B. 16 B16
34.

The result of the addition 37 16 +19 16 is 

A. 56 16
B. 60 16
C. 59 16
D. none of these
Answer» C. 59 16
35.

The 9 s compements of 381 is 

A. 372
B. 508
C. 618
D. 390
Answer» D. 390
36.

The 10 s complement of (715)is 

A. 63
B. 539
C. 285
D. 395
Answer» C. 285
37.

(r-1)s complement of the (r-1)s comple -ment of aninteganl number is 

A. origianl number
B. (r-2)s complement of the number
C. r s compliment
D. none of these
Answer» B. (r-2)s complement of the number
38.

A 17 bit binary number has an accuracy equivalent to the decimal fraction 

A. 1/1024
B. 1/2048
C. 1/4096
D. 1/6400
Answer» D. 1/6400
39.

The ASCII

A. is a subset of 8-bit EBCDIC
B. is used only in Western Countries
C. is version II of the ASC standaed
D. has 128 character including 32 control characters
Answer» E.
40.

Which one of the following is the result of dividing 0011 1000 by 1000 

A. (1100)
B. (1110)
C. (0011)
D. (0111)
Answer» E.
41.

The ASII code is 

A. number code
B. same as BCD code
C. an alphanumeic code
D. seldom used
Answer» D. seldom used
42.

The  octal equivalent of decimal 324.987 is 

A. 504.771
B. 540.781
C. 215.234
D. 40.987
Answer» B. 540.781
43.

What is the decimal equivalent of hexadecimal number 566

A. FF1
B. 1FF
C. 3FF
D. FF3
Answer» C. 3FF
44.

What is    the binary equivalent of the hexadeci -mal number B3

A. 10110001
B. 1101 0011
C. 1011 0011
D. 1001 0101
Answer» D. 1001 0101
45.

What is the hexadecimal equivalent   of binary  number 6060 6666

A. AF
B. 9E
C. 8C
D. none of these
Answer» B. 9E
46.

How many fractional digits 2-48 will have 

A. 24
B. 47
C. 49
D. 48
Answer» E.
47.

How many different number a 6 -bit binary word can represent 

A. 63
B. 64
C. 124
D. 32
Answer» C. 124
48.

Number 84 in BCD is 

A. 1000 0100
B. 01000100
C. 1000 101
D. 1000 1100
Answer» B. 01000100
49.

Even parity is being used for error checking computer data If data word to be transmitted is 01010111 the value of the parity will be 

A. 0
B. 1
C. 1 or 0
D. 01
Answer» C. 1 or 0
50.

When an old number is converted into the binary number the least significant digit (LSD) is 

A. 0
B. 1
C. 0 or 1
D. none of these
Answer» C. 0 or 1