Explore topic-wise MCQs in Testing Subject.

This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.

1.

In 8085 microprocessor, which of the following interrupts is unmaskable interrupts?

A. RST 5.5
B. RST 7.5
C. TRAP
D. INTR
Answer» D. INTR
2.

The code which provides for parity check is

A. Baudot
B. ASCII
C. EBCDIC
D. Excess-3
Answer» C. EBCDIC
3.

In ASCII, letter B is coded as

A. 1000001
B. 1000010
C. 100100
D. 1001000
Answer» C. 100100
4.

A typical microcomputer has 65, 536 registers in its memory. It will be specified as

A. 65.536 memory
B. 65.536 K memory
C. 64 K memory
D. 8 K memory
Answer» D. 8 K memory
5.

A JK flip flop can be converted to D flip flop by

A. Connecting both J and K terminals to D
B. Connecting J terminal to D and leaving K open
C. Connecting K terminal to D and leaving J open
D. Connecting J terminal to D and K terminal to D through an inverter
Answer» E.
6.

In which one of the following types of analog to digital convertors the conversion time is practically independent of the amplitude of the analog signal?

A. The dual slope integrating type
B. Successive approximation type
C. Counter ramp type
D. Tracking type
Answer» C. Counter ramp type
7.

A pair of 21114s can store __________ words of __________ bits each.

A. 2114, 8
B. 1024, 8
C. 4228, 16
D. 2114, 16
Answer» C. 4228, 16
8.

Hexadecimal number F is called to octal number

A. 15
B. 16
C. 17
D. 18
Answer» D. 18
9.

A divide by 78 counter can be obtained by

A. 6 numbers of mod-13 counters
B. 13 numbers of mod-6 counters
C. one mod-13 counter followed by mod-6 counter
D. 13 number of mod-13 counters
Answer» D. 13 number of mod-13 counters
10.

The ALU carrier out arithmetic and logic operations (OR AND, NOT, etc.) it processes

A. decimal numbers
B. binary numbers
C. hexadecimal numbers
D. octal numbers
Answer» C. hexadecimal numbers
11.

How is inversion achieved using EX-OR gate?

A. Giving input signal to the two input lines of the gate tied together
B. Giving input to one input line and logic one to the other line
C. Giving input to one input line and logic one to the other line
D. Inversion cannot be achieved using EX-OR gate
Answer» D. Inversion cannot be achieved using EX-OR gate
12.

26810 = __________ .

A. 10A16
B. 10B16
C. 10C16
D. 10D16
Answer» D. 10D16
13.

Which of them has 10 inputs and 4 outputs?

A. Decimal to BCD encoder
B. BCD to decimal decoder
C. Octal to binary encoder
D. All encoders
Answer» B. BCD to decimal decoder
14.

Dual slope ADC uses an op amp comparator.

A. 1
B.
Answer» B.
15.

The rate of change of digital signals between High and Low level is

A. very fast
B. fast
C. slow
D. very slow
Answer» B. fast
16.

Which is correct with respect to computer memory?

A. Only a particular address can have a particular memory
B. Any address can have any memory
C. To read a word from computer memory, it is not necessary to specify a location
D. None of the above
Answer» C. To read a word from computer memory, it is not necessary to specify a location
17.

Which of the following represents the decimal form of binary 0.0111?

A. 0.16
B. 0.22728
C. 0.9375
D. 0.7964
Answer» D. 0.7964
18.

The number of flip-flops needed to divide the input frequency by 32 is

A. 2
B. 4
C. 5
D. 16
Answer» D. 16
19.

In the assembler, which one of the following is required for variable name in symbol table?

A. Addresses
B. Values
C. Registers
D. Storage
Answer» D. Storage
20.

Which of these is the most recent display device?

A. LED
B. LCD
C. VF
D. (a) and (c)
Answer» D. (a) and (c)
21.

Assertion (A): The carry look ahead adder is very fast Reason (R): The carry look ahead adder generates the carry and sum digits directly.

A. Both A and R are correct and R is correct explanation of A
B. Both A and R are correct but R is not correct explanation of A
C. A is true, R is false
D. A is false, R is true
Answer» D. A is false, R is true
22.

BCD equivalent of - 810 is

A. 110
B. 10110
C. 11000
D. 1000
Answer» D. 1000
23.

For a level input sequential circuit

A. output in a level only
B. output is in the pulse form
C. output may be a pulse or a level form
D. none of these
Answer» B. output is in the pulse form
24.

In 8085, usually the vector location and the next two memory location contain a JMP instruction. This allows the programs to branch to

A. a longer subroutine
B. a shorter subroutine
C. a subroutine free path
D. none of the above
Answer» B. a shorter subroutine
25.

A 7477 decoder drives

A. seven-segment display
B. nickel tape
C. relays
D. diode matrix
Answer» B. nickel tape
26.

In 8085 microprocessor, what is the length of status Word?

A. 6 bits
B. 8 bits
C. 12 bits
D. 16 bits
Answer» E.
27.

A 4 bit ripple counter uses flip flops with propagation delay of 50 ns each. The maximum clock frequency which can be used is

A. 5 MHz
B. 10 MHz
C. 20 MHz
D. 25 MHz
Answer» B. 10 MHz
28.

Assertion (A): Divide-64 counter is a Mod-64 counter and divides the input frequency by 64 Reason (R): A Mod 64 counter can be obtained by cascading Mod 16 and Mod 4 counters.

A. Both A and R are correct and R is correct explanation of A
B. Both A and R are correct but R is not correct explanation of A
C. A is true, R is false
D. A is false, R is true
Answer» C. A is true, R is false
29.

What will be minimum conversion rate in 6 bit dual slope A/D converter uses a reference of -6v and a 1 MHz clock. It uses a fixed count of 40 (101000).

A. 9000
B. 9259
C. 1000
D. 1000
Answer» C. 1000
30.

The widely used binary multiplication method is

A. repeated addition
B. add and shift
C. shift and add
D. any of the above
Answer» C. shift and add
31.

Assuming accumulator contain A 64 and the carry is set (1). What will register A and carry (CY) contain after ORA A?

A. A 6 H, 1
B. A 6 H, 0
C. 00 H, 0
D. 00 H, 1
Answer» C. 00 H, 0
32.

Which of the following finds application in pocket calculators?

A. TTL
B. CMOS
C. ECL
D. Both (a) and (c)
Answer» C. ECL
33.

In one of the codes for transfer of numbers the code for the succeeding number differs from that of the number only in the change of a single digit. The code is

A. ASCII
B. Excess 3 CODE
C. Gray CODE
D. none of these
Answer» D. none of these
34.

Flag bits in arithmetic unit provide

A. status type information
B. repeatability
C. facilities for rechecks
D. all of the above
Answer» B. repeatability
35.

A hexadecimal odometer displays F52F. The next reading will be

A. E 52 F
B. E 52 E
C. E 53 F
D. F 53 O
Answer» E.
36.

Floating gate is fabricated for making MOS

A. ROM
B. PROM
C. EPROM
D. EAROM
Answer» D. EAROM
37.

Which of the following memories normally has highest storage capacity?

A. Magnetic disc
B. Magnetic tape
C. Semiconductor memory
D. Core memory
Answer» B. Magnetic tape
38.

Flow charts that contain decision symbol

A. represent straight line programs
B. do not represent straight line programs
C. all of the above
D. none of the above
Answer» C. all of the above
39.

If A = B = 1, the outputs P and Q in the given figure are

A. P = Q = 0
B. P = 0, Q = 1
C. P = 1, Q = 0
D. P = Q = 1
Answer» C. P = 1, Q = 0
40.

In DTL the junction transistor serves as

A. inverter
B. buffer amplifier
C. both (a) and (b)
D. none of the above
Answer» D. none of the above
41.

As compared to TTL, CMOS logic has

A. higher speed of operation
B. higher power dissipation
C. smaller physical size
D. all of the above
Answer» D. all of the above
42.

In the given figure, A = B = 1 and C = D = 0. Then Y =

A. 1
B. 0 
C. either 1 or 0
D. indeterminate
Answer» C. either 1 or 0
43.

Single parity check is not reliable in case of

A. paper tape
B. magnetic tape
C. magnetic drum
D. cores
Answer» D. cores
44.

For a binary half subtractor having two inputs A and B the correct sets of logical expressions for the outputs D (A - B) and X = Borrow are

A. D = AB + AB, X = AB
B. D = AB AB, X = AB
C. D = AB + AB, X = AB
D. D = AB + A B, X = AB
Answer» D. D = AB + A B, X = AB
45.

Which two rows represent identical binary numbers?

A. A second and fourth
B. Fifth and eight
C. Third and seventh
D. Second and third
Answer» E.
46.

An 8156 has A15 connected to its CE input. A14 to A8 are unconnected, and AD7 to AC0 are connected ignoring shadows, what are the RAM locations?

A. (4000)H - (40FF)H
B. (8000)H - (80FF)H
C. (8000)H - (40FF)H
D. Any of the above
Answer» C. (8000)H - (40FF)H
47.

In the circuit of the given figure, Y =

A. 0
B. 1
C. X
D. X
Answer» B. 1
48.

Programmable logic array uses

A. RAM matrices
B. ROMs matrices
C. PROM matrices
D. Silo memory
Answer» C. PROM matrices
49.

The binary equivalent of 4096.90625 is

A. 1000000000000
B. 10000000000000
C. 1000000000000
D. 1000000000000
Answer» B. 10000000000000
50.

The disadvantage of counter type ADC as compared to comparator ADC is that

A. resolution is low
B. conversion time is more
C. circuit is more complex
D. stability is low
Answer» B. conversion time is more