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Syllabus

NEC Computer · Practice

Chapters & sets

1. Basic Electrical and Electronics

Basic Electrical

Set 1106

Basic Electronics

Set 171 Set 233

2. Digital Logic and Microprocessor

Digital Logic

Set 150 Set 250 Set 350 Set 450 Set 550 Set 650 Set 749 Set 851 Set 950 Set 1050 Set 1150 Set 1232

Microprocessor

Set 150 Set 250 Set 350 Set 445 Set 550 Set 650 Set 720 Set 850 Set 969

3. Programming Language and Its Applications

Mixed chapter MCQs

Set 150 Set 249 Set 349 Set 451 Set 540

4. Computer Organization and Embedded System

Mixed chapter MCQs

Set 150 Set 249 Set 350 Set 450 Set 550 Set 650 Set 750 Set 849 Set 950 Set 1050 Set 1150

5. Concept of Computer Network and Network Security System

Basic Networking

Set 150 Set 253

Advanced Networking

Set 150 Set 250 Set 350 Set 450 Set 550 Set 655

6. Theory of Computation and Computer Graphics

Theory of Computation

Set 150 Set 250 Set 360

Computer Graphics

Set 150 Set 251 Set 350 Set 450 Set 550

7. Data Structures and Algorithm, Database System and Operating System

8. Software Engineering and Object-Oriented Analysis & Design

Mixed chapter MCQs

Set 150 Set 250 Set 350 Set 450 Set 550 Set 650 Set 750 Set 926

9. Artificial Intelligence and Neural Networks

Mixed chapter MCQs

Set 150 Set 317 Set 450 Set 550 Set 650 Set 750 Set 850 Set 932

10. Project Planning, Design and Implementation

Engineering Drawing

Set 150 Set 267

Engineering Economics

Set 168

Project Planning & Scheduling

Set 188

Project Mangement

Set 150

Engineering Professional Practice

Set 120

Engineering Regulatory Body

Set 130

Digital Logic Set 6

50 questions

Question 1

Which of the following is the faster logic?

A.
$\text{TTL}$
B.
$\text{CMOS}$
C.

50

\text{ECL}

D.

\text{LSI}

Question 2

If the input to a T-flip-flop is a 100 Hz signal, the final output of the three T-flip-flops in cascade is:

A.
$1000 \text{ Hz}$
B.
$333 \text{ Hz}$
C.
$500 \text{ Hz}$
D.
$12.5 \text{ Hz}$

Question 3

Which of the following memory is volatile memory?

A.
$\text{ROM}$
B.
$\text{PROM}$
C.
$\text{RAM}$
D.
$\text{EEPROM}$

Question 4

-8 is equal to the signed binary number:

A.
$10001000$
B.
$10000000$
C.
$00001000$
D.
$1000000$

Question 5

De Morgan's first theorem shows the equivalence of:

A.
$\text{OR gate and Exclusive OR gate}$
B.
$\text{NOR gate and Bubbled AND gate}$
C.
$\text{NOR gate and NAND gate}$
D.
$\text{NAND gate and NOT gate}$

Question 6

The digital logic family which has the lowest propagation delay time is:

A.
$\text{ECL}$
B.
$\text{CMOS}$
C.
$\text{TTL}$
D.
$\text{PMOS}$

Question 7

The device which changes from serial data to parallel data is:

A.
$\text{Counter}$
B.
$\text{Demultiplexer}$
C.
$\text{Multiplexer}$
D.
$\text{Flip-flop}$

Question 8

A device which converts BCD to Seven Segment is called:

A.
$\text{Encoder}$
B.
$\text{Multiplexer}$
C.
$\text{Decoder}$
D.
$\text{De-multiplexer}$

Question 9

In a JK Flip-Flop, toggle means:

A.
$\text{Set } Q = 1 \text{ and } \overline{Q} = 0$
B.
$\text{Set } Q = 0 \text{ and } \overline{Q} = 1$
C.
$\text{Change the output to the opposite state}$
D.
$\text{No change in output}$

Question 10

The access time of ROM using bipolar transistors is about:

A.
$1 \text{ sec}$
B.
$1 \text{ psec}$
C.
$1 \text{ msec}$
D.
$\text{nsec}$

Question 11

The A/D converter whose conversion time is independent of the number of bits is:

A.
$\text{Dual slope}$
B.
$\text{Parallel conversion}$
C.
$\text{Counter type}$
D.
$\text{Successive approximation}$

Question 12

When signed numbers are used in binary arithmetic, which notation has a unique representation for zero?

A.
$\text{Sign-magnitude}$
B.
$\text{2's complement}$
C.
$\text{1's complement}$
D.
$\text{9's complement}$

Question 13

A hexadecimal odometer displays F52F. The next reading will be:

A.
$F52F$
B.
$F530$
C.
$F53F$
D.
$F530$

Question 14

Most digital computers do not have floating-point hardware because:

A.
$\text{Floating-point hardware is costly}$
B.
$\text{It is slower than software}$
C.
$\text{It is not possible to perform floating-point addition by hardware}$
D.
$\text{No specific reason}$

Question 15

In digital ICs, Schottky transistors are preferred over normal transistors because of their:

A.
$\text{Lower propagation delay}$
B.
$\text{Lower power dissipation}$
C.
$\text{Higher propagation delay}$
D.
$\text{Higher power dissipation}$

Question 16

The following switching functions are to be implemented using a Decoder: ( f_1 = \sum m(1, 2, 4, 8, 10, 14) )\ ( f_2 = \sum m(2, 5, 9, 11) )\ ( f_3 = \sum m(2, 4, 5, 6, 7) )\ The minimum configuration of the decoder should be:

A.
$2-to-4 \text{ line}$
B.
$4-to-16 \text{ line}$
C.
$3-to-8 \text{ line}$
D.
$5-to-32 \text{ line}$

Question 17

A 4-bit synchronous counter uses flip-flops with propagation delay times of 15 ns each. The maximum possible time required for a change of state is:

A.
$15 \text{ ns}$
B.
$45 \text{ ns}$
C.
$30 \text{ ns}$
D.
$60 \text{ ns}$

Question 18

Words having 8-bits are to be stored into computer memory. The number of lines required for writing into memory are:

A.
$1$
B.
$4$
C.
$2$
D.
$8$

Question 19

In a successive-approximation A/D converter, offset voltage equal to 1/2 LSB is added to the D/A converter's output. This is done to:

A.
$\text{Improve the speed of operation}$
B.
$\text{Reduce the maximum quantization error}$
C.
$\text{Increase the number of bits at the output}$
D.
$\text{Increase the range of input voltage that can be converted}$

Question 20

The decimal equivalent of the binary number 11010 is:

A.
$26$
B.
$16$
C.
$36$
D.
$23$

Question 21

The 1's complement representation of the decimal number -17 using 8-bit representation is:

A.
$11101110$
B.
$11001100$
C.
$11011101$
D.
$00010001$

Question 22

The excess-3 code of the decimal number 26 is:

A.
$01001001$
B.
$10001001$
C.
$01011001$
D.
$01001101$

Question 23

How many AND gates are required to realize ( Y = CD + EF + G )?

A.
$4$
B.
$3$
C.
$5$
D.
$2$

Question 24

How many select lines will a 16-to-1 multiplexer have?

A.
$4$
B.
$5$
C.
$3$
D.
$1$

Question 25

How many flip-flops are required to construct a decade counter?

A.
$10$
B.
$4$
C.
$3$
D.
$2$

Question 26

Which TTL logic gate is used for wired ANDing?

A.
$\text{Open collector output}$
B.
$\text{Tristate output}$
C.
$\text{Totem Pole}$
D.
$\text{ECL gates}$

Question 27

CMOS circuits consume power:

A.
$\text{Equal to TTL}$
B.
$\text{Twice of TTL}$
C.
$\text{Less than TTL}$
D.
$\text{Thrice of TTL}$

Question 28

In a RAM, information can be stored:

A.
$\text{By the user, number of times}$
B.
$\text{By the user, only once}$
C.
$\text{By the manufacturer, a number of times}$
D.
$\text{By the manufacturer only once}$

Question 29

The hexadecimal number for ( (95.5)_{10} ) is:

A.
$(5F.8)_{16}$
B.
$(2E.F)_{16}$
C.
$(9A.B)_{16}$
D.
$(5A.4)_{16}$

Question 30

The octal equivalent of ( (247)_{10} ) is:

A.
$(252)_8$
B.
$(367)_8$
C.
$(350)_8$
D.
$(400)_8$

Question 31

The chief reason why digital computers use complemented subtraction is that it:

A.
$\text{Simplifies the circuitry}$
B.
$\text{Is a very simple process}$
C.
$\text{Can handle negative numbers easily}$
D.
$\text{Avoids direct subtraction}$

Question 32

In a positive logic system, logic state 1 corresponds to:

A.
$\text{Positive voltage}$
B.
$\text{Zero voltage level}$
C.
$\text{Higher voltage level}$
D.
$\text{Lower voltage level}$

Question 33

The commercially available 8-input multiplexer integrated circuit in the TTL family is:

A.
$7495$
B.
$74154$
C.
$74153$
D.
$74151$

Question 34

CMOS circuits are extensively used for on-chip computers mainly because of their extremely:

A.
$\text{Low power dissipation}$
B.
$\text{Large packing density}$
C.
$\text{High noise immunity}$
D.
$\text{Low cost}$

Question 35

The MSI chip 7474 is:

A.
$\text{Dual edge-triggered JK flip-flop (TTL)}$
B.
$\text{Dual edge-triggered D flip-flop (CMOS)}$
C.
$\text{Dual edge-triggered D flip-flop (TTL)}$
D.
$\text{Dual edge-triggered JK flip-flop (CMOS)}$

Question 36

Which of the following memories stores the most number of bits?

A.
$\text{A 5Mx8 memory}$
B.
$\text{A 5Mx4 memory}$
C.
$\text{A 1Mx16 memory}$
D.
$\text{A 1Mx12 memory}$

Question 37

The process of entering data into a ROM is called:

A.
$\text{Burning in the ROM}$
B.
$\text{Changing the ROM}$
C.
$\text{Programming the ROM}$
D.
$\text{Charging the ROM}$

Question 38

When the set of input data to an even parity generator is 0111, the output will be:

A.
$1$
B.
$\text{Unpredictable}$
C.
$0$
D.
$\text{Depends on the previous input}$

Question 39

The number 140 in octal is equivalent to:

A.
$(96)_{10}$
B.
$(90)_{10}$
C.
$(86)_{10}$
D.
$\text{None of these}$

Question 40

The NOR gate output will be high if the two inputs are:

A.
$00$
B.
$10$
C.
$01$
D.
$11$

Question 41

Which of the following is the fastest logic?

A.
$\text{ECL}$
B.
$\text{CMOS}$
C.
$\text{TTL}$
D.
$\text{LSI}$

Question 42

How many flip-flops are required to construct a mod-30 counter?

A.
$5$
B.
$4$
C.
$6$
D.
$8$

Question 43

How many address bits are required to represent a 32K memory?

A.
$10 \text{ bits}$
B.
$14 \text{ bits}$
C.
$12 \text{ bits}$
D.
$16 \text{ bits}$

Question 44

The number of control lines for a 16-to-1 multiplexer is:

A.
$2$
B.
$3$
C.
$4$
D.
$5$

Question 45

Which of the following requires refreshing?

A.
$\text{SRAM}$
B.
$\text{ROM}$
C.
$\text{DRAM}$
D.
$\text{EPROM}$

Question 46

Shifting a register content to the left by one bit position is equivalent to:

A.
$\text{Division by two}$
B.
$\text{Multiplication by two}$
C.
$\text{Addition by two}$
D.
$\text{Subtraction by two}$

Question 47

For a JK flip-flop with ( J = 1 ) and ( K = 0 ), the output after a clock pulse will be:

A.
$0$
B.
$\text{High impedance}$
C.
$1$
D.
$\text{No change}$

Question 48

Convert decimal 153 to octal. The equivalent in octal will be:

A.
$(231)_8$
B.
$(431)_8$
C.
$(331)_8$
D.
$\text{None of these}$

Question 49

The decimal equivalent of

( (1100)_2 )

is:

A.
$12$
B.
$18$
C.
$16$
D.
$20$

Question 50

The binary equivalent of

( (FA)_{16} )

is:

A.
$10101111$
B.
$10110011$
C.
$11111010$
D.
$\text{None of these}$

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