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.

101.

How many gates (minimum ) are needed for a 3-bit up-counter using standard binary and using T flip-flops ? Assume unlimited fan-in.

A. 4
B. 3
C. 2
D. 1
Answer» E.
102.

The number of clock pulses needed to shift one byte of data from input to the output of a 4-bit shift register is 

A. 11
B. 12
C. 16
D. 32
Answer» D. 32
103.

A 2 MHz signal is applied to the input of a J-K flip-flop which is operating in the 'toggle' mode. the frequency of the signal at the output will be 

A. 1 MHz
B. 2 MHz
C. 4 MHz
D. 8 MHz
Answer» B. 2 MHz
104.

A J-K flip-flop has its J-input connected to logic level 1 and its input to the Q output pulse is fed to its clock input the flip-flop will now 

A. change its state at each clock pulse
B. go to state 1 and stay there
C. go to state 0 and stay there
D. retain its previous state
Answer» B. go to state 1 and stay there
105.

In a positive edge triggered JK flip-flop, a low J and low K produces 

A. no change
B. low state
C. high state
D. toggle
Answer» C. high state
106.

In a ripple counter using edge triggered JK filp-flops, the pulse input is applied to the 

A. clock input of all flip-flops
B. clock input of one flip-flops
C. J and K inputs of all flip-flops
D. J and K inputs of one flip-flop
Answer» C. J and K inputs of all flip-flops
107.

Flip-flop outputs are always 

A. complimentary
B. the same
C. independent of each other
D. same as inputs
Answer» E.
108.

Consider an RS flip-flops with both inputs set to 0. if a momentary '1' is applied at the input S, then the output 

A. Q will flip from 0 to 1
B. Q will flip from 0 to 1 and then back to 0
C. Q will flip from 1 to 0
D. Q will flip from 0 to 1 and then back to 0
Answer» D. Q will flip from 0 to 1 and then back to 0
109.

The output of a sequential circuit depends on 

A. present inputs only
B. past inputs only
C. both present and past inputs
D. present outputs only
Answer» E.
110.

74 LS138 chip functions as 

A. decoder /demultiplexer
B. encoder
C. multiplexer
D. memory element
Answer» C. multiplexer
111.

A shift register can be used for 

A. parallel to serial conversion
B. serial to parallel conversion
C. digital delay line
D. all of these
Answer» B. serial to parallel conversion
112.

What is the maximum counting speed of a 4-bit binary counter which is composed of flip-flops with a propagation delay of 25 ns ?

A. 1 MHz
B. 10 MHz
C. 100 MHz
D. 4 MHz
Answer» B. 10 MHz
113.

The number of flip-flops required in a decade counter is 

A. 3
B. 4
C. 5
D. 10
Answer» C. 5
114.

How many flip-flop are needed to divide the input frequency by 64 ? 

A. 4
B. 5
C. 6
D. 8
Answer» B. 5
115.

The master slave JK flip-flop is effectively a combination of 

A. a SR flip-flop and a T flip-flop
B. an SR flip-flop and a D flip-flop
C. a T flip-flop and a D flip-flop
D. tow T flip-flops
Answer» D. tow T flip-flops
116.

The functional difference between SR flip-flop and JK flip-flop is that JK flip-flop 

A. is faster than SR flip-flop
B. has a feed back path
C. accepts both inputs 1
D. dose not require external clock
Answer» D. dose not require external clock
117.

When an inverter is placed between both inputs of an SR flip-flop, then resulting flip-flop is 

A. JK flip-flop
B. D flip-flop
C. T flip-flop
D. Master slave JK flip-flop
Answer» E.
118.

How many bits are required to encode all twenty  six letters, ten symbols, and ten numerals ?

A. 5
B. 6
C. 7
D. 46
Answer» D. 46
119.

A sequential circuit outputs a ONE when an even number (> 0) of one's are input; otherwise the output is ZERO. The minimum number of states required is

A. 0
B. 1
C. 2
D. 3
Answer» C. 2
120.

The clock signals are used in sequential logic circuits to 

A. tell the time of the day
B. tell how much time has elapsed since the system was turned on
C. carry serial data signals
D. synchronize events in various parts of system
Answer» B. tell how much time has elapsed since the system was turned on
121.

A graphical display of the fundamental products in a truth-table is known as 

A. mapping
B. graphing
C. T-map
D. kanangh-map
Answer» E.
122.

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

remains unchanged after 

A. two of these literals are interchanged
B. any permutation of the literals
C. all the literals are changed in anticlockwise order
D. all the literals are changed in clockwise order
Answer» C. all the literals are changed in anticlockwise order
123.

Which of the following statements is true 

A. (A+B) (A+C)=AC+BC
B. (A+B) (A+C) =AB +C
C. (A+B) (A+C) =A+BC
D. (A+B) (A+C)=AC+B
Answer» D. (A+B) (A+C)=AC+B
124.

The Time required for a pulse to change from 10 to 90 percent of its maximum value is Called

A. rise time
B. decay time
C. propagation time
D. operating speed
Answer» B. decay time
125.

The time Required for a gate or inverter to change its state is called

A. rise time
B. decay time
C. propagation time
D. charging time
Answer» D. charging time
126.

The number of canonical expressions that can be 

developed over a 3-valued boolean algebra is 

A. 8
B. 16
C. 32
D. 64
Answer» E.
127.

Simplified form of the boolean expression 

(X+Y+XY) (X+Z) is 

A. X+Y+Z
B. XY+YZ
C. X+YZ
D. XZ+Y
Answer» D. XZ+Y
128.

SMD on a data sheet for an IC means 

A. Single Memory Device
B. Serial Mode Data
C. Synchronous Mode Device
D. Surface Mount Device
Answer» E.
129.

The functional capacity for VLSI devices is 

A. 1 to 11 gates
B. 12 to 99 gates
C. 100 to 10000 gates
D. more than 10000 gates
Answer» E.
130.

The functional capacity for LSI devices is 

A. 1 to 11 gates
B. 12 to 99 gates
C. 100 to 10000 gates
D. more than 1000 gates
Answer» D. more than 1000 gates
131.

The operation which is commutative but not associative is 

A. AND
B. OR
C. EX-OR
D. NAND
Answer» E.
132.

Analog methods are not used for handling extremely precise information because 

A. precise information always involves numbers which are inherently digital
B. there are limits to how closely an analog signal can reproduce the information
C. analog information never need to be precise
D. they are very expensive
Answer» C. analog information never need to be precise
133.

A digital gate can respond to an input signal in 

A. about a second
B. about a hundredth of a second
C. a few billionth of a second
D. a few millisecond
Answer» D. a few millisecond
134.

Digatal circuits easier to design than analog circuits because 

A. they do not control electricity precisely over a wide range
B. they are made in the from of ICs
C. all elements of digital circuits are from the same family
D. they are smaller in size
Answer» B. they are made in the from of ICs
135.

Analog systems are different from digital systems because they

A. use transistors
B. handle information in analog from
C. handle information in digital form
D. are slow
Answer» C. handle information in digital form