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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

Basic Electronics Set 2

33 questions

Question 1

A Wien bridge oscillator uses ______ feedback.

A.
Only positive
B.
Only negative
C.
Both positive and negative
D.
None of the above

Question 2

50

The piezoelectric effect in a crystal is ______.

A.
A voltage developed because of mechanical stress
B.
A change in resistance because of temperature
C.
A change in frequency because of temperature
D.
None of the above

Question 3

If the crystal frequency changes with temperature, we say that crystal has ______ temperature coefficient.

A.
Positive
B.
Zero
C.
Negative
D.
None of the above

Question 4

The crystal oscillator frequency is very stable due to ______ of the crystal.

A.
Rigidity
B.
Vibrations
C.
Low Q
D.
High Q

Question 5

An oscillator differs from an amplifier because it ______.

A.
Has more gain
B.
Requires no input signal
C.
Requires no D.C. supply
D.
Always has the same input

Question 6

For an oscillator to properly start, the gain around the feedback loop must initially be ______.

A.
1
B.
Greater than 1
C.
Less than 1
D.
Equal to attenuation of feedback circuit

Question 7

A class A power amplifier uses ______.

A.
Two transistors
B.
One transistor
C.
Three transistors
D.
Four transistors

Question 8

The maximum efficiency of resistance loaded class A power amplifier is ______.

A.
5%
B.
35%
C.
25%
D.
50%

Question 9

The maximum efficiency of transformer coupled class A power amplifier is ______.

A.
50%
B.
25%
C.
30%
D.
5%

Question 10

Power amplifiers handle ______ signals compare to voltage amplifiers.

A.
Small
B.
Large
C.
Very small
D.
Equal

Question 11

In class A operation, the operating point is generally located ______ of the D.C. load line.

A.
At cut off point
B.
At the middle
C.
At saturation point
D.
In active region

Question 12

A power amplifier has comparatively ______ β.

A.
Small
B.
Large
C.
Very large
D.
Same

Question 13

A class A power amplifier is sometimes called ______ amplifier.

A.
Reciprocating
B.
Single - ended
C.
Symmetrical
D.
Differential

Question 14

When no signal is applied, the approximate collector efficiency of class A power amplifier is ______.

A.
25%
B.
10%
C.
0%
D.
50%

Question 15

The maximum A.C. power output from a class A power amplifier is 10 W. What should be the minimum power rating of the transistor used?

A.
20W
B.
5 W
C.
25W
D.
50W

Question 16

The most costly coupling is ______ coupling.

A.
Transformer
B.
Impedance
C.
RC
D.
Direct

Question 17

Where does the Q point lie for class B amplifier?

A.
Active
B.
Cut off
C.
Saturation
D.
Between saturation and active

Question 18

What happens when class B amplifier is in a quiescent state?

A.
No current flows through the transistor
B.
Maximum current flows through the transistor
C.
Half of the maximum current flows through the transistor
D.
Quarter of the maximum current flows

Question 19

What is the value of the maximum efficiency of the class B amplifier?

A.
25%
B.
35%
C.
35% to 50%
D.
50% to 70%

Question 20

What kind of design is used to avoid transformer usage?

A.
High resistance
B.
Matched load
C.
Complementary symmetry
D.
Capacitive Model

Question 21

What is cross over distortion?

A.
Effect occurred during switching of transistor after every half cycle
B.
Distortion occurred due to resistors
C.
Distortion occurred due to Capacitors
D.
Distortion occurred due to Inductors

Question 22

How to avoid cross over distortion?

A.
By using more resistance
B.
By using more capacitance
C.
By using more Inductance
D.
By shifting the Q point above cut off

Question 23

For a Class B amplifier, the utilized load power is 300W and the Dc power is 500W, find efficiency.

A.
30%
B.
60%
C.
90%
D.
100%

Question 24

What is the conduction angle for Class B push-pull amplifier?

A.
0°
B.
90°
C.
180°
D.
270°

Question 25

A power transistor is a ______.

A.
Three layer, three junction device
B.
Three layer, two junction device
C.
Two layer, one junction device
D.
Four layer, three junction device

Question 26

For a power transistor, if base current IB is increased keeping Vcc constant; then ______.

A.
Ic increases
B.
Ic decreases
C.
Ic remains constant
D.
Ic changes sinusoidal

Question 27

Insulated-gate bipolar transistor (IGBT) has combinational advantages of ______.

A.
BJTs and SITs
B.
BJTs and MOSFETs
C.
SITs and MOSFETs
D.
FETs and BJTs

Question 28

A Gate Turn Off (GTO) can be turned on by applying ______.

A.
Positive gate signal
B.
Positive drain signal
C.
Positive source signal
D.
Negative source signal

Question 29

The turn on time of an SCR with inductive load is 20 μs. The pulse train frequency is 2.5 KHz with a mark/space ratio of 1/10, and then SCR will ______.

A.
Turn On
B.
Not turn on
C.
Turn on if inductance is removed.
D.
Turn on if pulse frequency is increased to two times

Question 30

What are the three terminals of a power MOSFET called?

A.
Collector, emitter, Gate
B.
Drain, source, gate
C.
Collector, emitter, base
D.
Drain, emitter, base

Question 31

A thyristor can be termed as ______.

A.
AC switch
B.
DC switch
C.
Wave switch
D.
Square wave switch

Question 32

In a series R-L-C circuit at resonance ______.

A.
$\omega LC = 1$
B.
$\omega L^2 C^2 = 1$
C.
$\omega^2 LC = 1$
D.
$\omega^2 L^2 C = 1$

Question 33

The power factor of a series R-L-C circuit at its half-power points is ______.

A.
Unity
B.
Lagging
C.
Leading
D.
Lagging or leading

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