Official Paper

RRB JE CBT 2 (Electrical and Allied Engineering) Official Paper (Held On: 2 Jul, 2026) (Previous Year Paper)

150 questions · 120 minutes · with answers · free

Attempt as Timed Mock Test

General Abilities (50 questions)

1

Which condition is required for a displacement reaction between a metal and salt solution?

  1. ((a))

    Metal must be same as salt constituent

  2. ((b))

    Metal must be higher in reactivity series

  3. ((c))

    Reaction must be endothermic

  4. ((d))

    Salt must be insoluble in water

Show Answer
Answer: ((a))

Metal must be same as salt constituent

2

According to the Article 75 of the Indian Constitution, the total number of ministers (including the Prime Minister) in the Council of Ministers shall NOT exceed what percentage of the total members of the House of the People, i.e., Lok Sabha?

  1. ((a))

    25%

  2. ((b))

    20%

  3. ((c))

    15%

  4. ((d))

    10%

Show Answer
Answer: ((a))

25%

3

A construction worker needs to lift a heavy metal beam using a lever but has a limited length of plank. Which adjustment would allow the worker to lift the beam with the least effort if the position of the fulcrum can be changed but the plank length remains constant?

  1. ((a))

    Keep the fulcrum fixed at any point

  2. ((b))

    Move the fulcrum closer to the beam

  3. ((c))

    Place the fulcrum at the center of the plank

  4. ((d))

    Move the fulcrum closer to the worker

Show Answer
Answer: ((a))

Keep the fulcrum fixed at any point

4

What file extension is used to save an MS PowerPoint 2021 presentation?

  1. ((a))

    .docx

  2. ((b))

    .xlsx

  3. ((c))

    .pdf

  4. ((d))

    .pptx

Show Answer
Answer: ((a))

.docx

5

According to Thomson’s model, how are electrons arranged in an atom?

  1. ((a))

    Randomly placed inside the nucleus

  2. ((b))

    Orbiting around neutrons in elliptical paths

  3. ((c))

    Embedded in a positively charged sphere like seeds in a watermelon

  4. ((d))

    Moving in fixed orbits around the nucleus

Show Answer
Answer: ((a))

Randomly placed inside the nucleus

6

A student pushes a heavy box that is already moving across a rough floor. If the force applied by the student is exactly equal to the frictional force opposing the motion, what will happen to the box?

  1. ((a))

    The box will move at a constant speed

  2. ((b))

    The box will move at increasing speed

  3. ((c))

    The box will gradually come to rest

  4. ((d))

    The box will accelerate forward

Show Answer
Answer: ((a))

The box will move at a constant speed

7

What is the main reason sulfur dioxide irritates the upper respiratory mucous membrane?

  1. ((a))

    It dissolves in moisture in upper respiratory tract and forms irritant

  2. ((b))

    It combines with other pollutants and polymerizes in the lungs

  3. ((c))

    It combines with haemoglobin and effect the oxygen transport

  4. ((d))

    It oxidizes to sulphur trioxide and inhaled deep into lung

Show Answer
Answer: ((a))

It dissolves in moisture in upper respiratory tract and forms irritant

8

Which type of computer virus attaches itself to executable files and gets activated when the file is run?

  1. ((a))

    Worm

  2. ((b))

    Macro Virus

  3. ((c))

    Boot Sector Virus

  4. ((d))

    File Infector Virus

Show Answer
Answer: ((a))

Worm

9

Which of the following statements is true about the Outbox?

  1. ((a))

    It is used to receive incoming emails.

  2. ((b))

    It contains emails that are currently being drafted.

  3. ((c))

    It temporarily stores emails that are queued for sending.

  4. ((d))

    It holds emails that have been successfully sent.

Show Answer
Answer: ((a))

It is used to receive incoming emails.

10

Which experimental discovery contradicted Thomson's model of the atom and led to its rejection?

  1. ((a))

    Discovery of the neutron by James Chadwick

  2. ((b))

    Alpha particle scattering showing deflection at large angles

  3. ((c))

    Measurement of atomic radius using X-ray diffraction

  4. ((d))

    Observation of line spectra of hydrogen by Bohr

Show Answer
Answer: ((a))

Discovery of the neutron by James Chadwick

11

If cell A1 = 10 and B1 = 20, what will =A1+B1 return?

  1. ((a))

    200

  2. ((b))

    30

  3. ((c))

    Error

  4. ((d))

    1020

Show Answer
Answer: ((a))

200

12

In a real-life scenario, a chemist discovers a compound with the formula CH3CH2CH(CH3)CH2CH2OH. What is the correct IUPAC name for this compound?

  1. ((a))

    3-methylhexanol

  2. ((b))

    4-methylpentanol

  3. ((c))

    3-methylpentan-1-ol

  4. ((d))

    2-methylhexanol

Show Answer
Answer: ((a))

3-methylhexanol

13

Which pair of sectors is commonly addressed together in State Action Plan on Climate Change (SAPCC) adaptation planning?

  1. ((a))

    Heavy industry and entertainment

  2. ((b))

    Information technology and space research

  3. ((c))

    Textile design and fashion marketing

  4. ((d))

    Water resources and health systems

Show Answer
Answer: ((a))

Heavy industry and entertainment

14

The Atal Bhujal Yojana 2020 focused on improving water resources management of how many states?

  1. ((a))

    eight

  2. ((b))

    ten

  3. ((c))

    five

  4. ((d))

    seven

Show Answer
Answer: ((a))

eight

15

Who won the maximum number of medals at the 38th National Games of India?

  1. ((a))

    Manu Bhaker

  2. ((b))

    Neeraj Chopra

  3. ((c))

    Bajrang Punia

  4. ((d))

    Dhinidhi Desinghu

Show Answer
Answer: ((a))

Manu Bhaker

16

Which of the following best describes how sound travels through air?

  1. ((a))

    The air particles vibrate up and down perpendicular to the direction of the wave

  2. ((b))

    The air particles move in circular paths as the wave passes

  3. ((c))

    The air particles remain stationary while the wave moves through

  4. ((d))

    The air particles vibrate back and forth parallel to the direction of the wave

Show Answer
Answer: ((a))

The air particles vibrate up and down perpendicular to the direction of the wave

17

Which of the following Articles states about the right of individual to form associations or unions or co-operative societies?

  1. ((a))

    Article 19 (1) (c)

  2. ((b))

    Article 19 (1) (b)

  3. ((c))

    Article 19 (1) (a)

  4. ((d))

    Article 19 (1) (d)

Show Answer
Answer: ((a))

Article 19 (1) (c)

18

The primary method of managing biodegradable domestic waste after collection is _________________.

  1. ((a))

    burnt in open air

  2. ((b))

    conversion into compost

  3. ((c))

    sending for recycling

  4. ((d))

    throwing into sewers

Show Answer
Answer: ((a))

burnt in open air

19

Which Quick Style type is applied only to selected words or individual characters within a paragraph in MS Word 2010?

  1. ((a))

    Character styles

  2. ((b))

    Paragraph styles

  3. ((c))

    Page styles

  4. ((d))

    Linked styles

Show Answer
Answer: ((a))

Character styles

20

If 10 grams of salt are dissolved in 100 mL of water, which component is the solute?

  1. ((a))

    Neither

  2. ((b))

    Salt only

  3. ((c))

    Water only

  4. ((d))

    Both salt and water

Show Answer
Answer: ((a))

Neither

21

The pollutant group commonly associated with oil spills in oceans is ______________.

  1. ((a))

    synthetic detergents

  2. ((b))

    petroleum products

  3. ((c))

    agricultural pesticides

  4. ((d))

    chemical fertilizers

Show Answer
Answer: ((a))

synthetic detergents

22

Which of the following best describes the velocity-time graph for an object moving with uniform velocity?

  1. ((a))

    A straight horizontal line parallel to the time axis

  2. ((b))

    A curved line above the time axis

  3. ((c))

    A straight line sloping upwards from the time axis

  4. ((d))

    A line starting from the origin and sloping upwards

Show Answer
Answer: ((a))

A straight horizontal line parallel to the time axis

23

A student accidentally spills some hydrochloric acid on a table. Which substance should be used to neutralise the acid safely?

  1. ((a))

    Lemon juice

  2. ((b))

    Baking soda solution

  3. ((c))

    Sugar solution

  4. ((d))

    Vinegar

Show Answer
Answer: ((a))

Lemon juice

24

The atmospheric component that remains largely unreactive is _____________.

  1. ((a))

    Carbon dioxide

  2. ((b))

    Methane

  3. ((c))

    Oxygen

  4. ((d))

    Argon

Show Answer
Answer: ((a))

Carbon dioxide

25

Which of the following satellites was launched on November 2, 2025, to enhance the Indian Navy’s secure communication network and maritime surveillance capabilities?

  1. ((a))

    RISAT-2B

  2. ((b))

    GSAT-6A

  3. ((c))

    CMS-03 (GSAT-7R)

  4. ((d))

    Cartosat-3

Show Answer
Answer: ((a))

RISAT-2B

26

Which of the following rivers forms a delta along the eastern coastal plains?

  1. ((a))

    Tapi

  2. ((b))

    Narmada

  3. ((c))

    Godavari

  4. ((d))

    Ganga

Show Answer
Answer: ((a))

Tapi

27

Which new warship was commissioned by the Indian Navy in November, 2025, to strengthen anti-submarine and coastal defence capabilities?

  1. ((a))

    INS Vikrant

  2. ((b))

    INS Mahe

  3. ((c))

    INS Ikshak

  4. ((d))

    INS Arnala

Show Answer
Answer: ((a))

INS Vikrant

28

The primary goal of the Pradhan Mantri Gram Sadak Yojana (PMGSY) is to:

  1. ((a))

    Develop urban infrastructure

  2. ((b))

    Provide rural connectivity through road construction

  3. ((c))

    Enhance telecommunication services in cities

  4. ((d))

    Promote renewable energy usage

Show Answer
Answer: ((a))

Develop urban infrastructure

29

Which of the following is/are the primary reasons to fall in the trap of Email fraud or phishing?
A) Paying attention to lucrative offers.
B) Not checking on links or attachments from unknown senders
C) Providing official information via email
D) Paying attention to the company logo sent in the email

  1. ((a))

    A, B Only

  2. ((b))

    A, B, D Only

  3. ((c))

    A, B, C Only

  4. ((d))

    A only

Show Answer
Answer: ((a))

A, B Only

30

The Kol Rebellion (1831–32) mainly affected which plateau region?

  1. ((a))

    Meghalaya Plateau

  2. ((b))

    Deccan Plateau

  3. ((c))

    Malwa Plateau

  4. ((d))

    Chotanagpur Plateau

Show Answer
Answer: ((a))

Meghalaya Plateau

31

A farmer applies large amounts of chemical fertilizers over several years. Which consequence most likely results from this practice leading to soil pollution?

  1. ((a))

    Erosion of surface soil layers

  2. ((b))

    Faster plant growth every season

  3. ((c))

    Increase in earthworm population

  4. ((d))

    Accumulation of toxic substances in soil

Show Answer
Answer: ((a))

Erosion of surface soil layers

32

Which British colonial building in Mumbai, completed in 1888, showcases a blend of Victorian Gothic and Indian architectural elements?

  1. ((a))

    Chhatrapati Shivaji Maharaj Terminus

  2. ((b))

    Gateway of India

  3. ((c))

    Rajabai Clock Tower

  4. ((d))

    Bombay Town Hall

Show Answer
Answer: ((a))

Chhatrapati Shivaji Maharaj Terminus

33

Which of the following statements best describes the behavior of magnetic field lines around a straight current-carrying conductor?

  1. ((a))

    They change direction randomly along the wire.

  2. ((b))

    They radiate straight outward from the wire.

  3. ((c))

    They form concentric circles centered on the conductor.

  4. ((d))

    They are parallel straight lines along the wire.

Show Answer
Answer: ((a))

They change direction randomly along the wire.

34

Consider the following statements regarding chemical reactions and choose the correct option.

Statement I: Every reaction in which two or more reactants combine to form a single product is classified as a combination reaction regardless of heat change.

Statement II: The reaction CaO(s) + H2O(l) → Ca(OH)2(aq) + heat is both a combination reaction and an exothermic reaction.

  1. ((a))

    Both statements are incorrect

  2. ((b))

    Both statements are correct

  3. ((c))

    Only Statement II is correct

  4. ((d))

    Only Statement I is correct

Show Answer
Answer: ((a))

Both statements are incorrect

35

How can we locate a file with a known extension but an unknown name in a large directory?

  1. ((a))

    Using the dir command

  2. ((b))

    Using the Search box in File Explorer with *.ext

  3. ((c))

    Checking the Recycle Bin

  4. ((d))

    Through File Explorer

Show Answer
Answer: ((a))

Using the dir command

36

When was the 11th National Handloom Day celebrated across India under the coordination of the Ministry of Textiles?

  1. ((a))

    September 7, 2025

  2. ((b))

    November 7, 2025

  3. ((c))

    August 7, 2025

  4. ((d))

    October 7, 2025

Show Answer
Answer: ((a))

September 7, 2025

37

Which function returns the smallest value?

  1. ((a))

    AVERAGE

  2. ((b))

    COUNT()

  3. ((c))

    MAX()

  4. ((d))

    MIN()

Show Answer
Answer: ((a))

AVERAGE

38

A field exposed to excessive pesticide use shows a sharp decline in earthworm population. The resulting effect on soil is:

  1. ((a))

    Reduced soil fertility

  2. ((b))

    Enhanced decomposition

  3. ((c))

    Increased water retention

  4. ((d))

    Improved aeration

Show Answer
Answer: ((a))

Reduced soil fertility

39

Which of the following statements best describes how the power of accommodation enables the human eye to focus on both near and distant objects?

  1. ((a))

    The cornea provides all the focusing power required for clear vision

  2. ((b))

    The eye lens changes its focal length by altering its shape through ciliary muscle action

  3. ((c))

    The iris controls the amount of light entering and helps to focus

  4. ((d))

    The retina moves forward and backward to adjust the focus

Show Answer
Answer: ((a))

The cornea provides all the focusing power required for clear vision

40

On which date is National Handloom Day observed in India?

  1. ((a))

    2 October

  2. ((b))

    18 August

  3. ((c))

    5 September

  4. ((d))

    7 August

Show Answer
Answer: ((a))

2 October

41

What is the general formula of alkenes?

  1. ((a))

    CnHn

  2. ((b))

    CnH2n−2

  3. ((c))

    CnH2n

  4. ((d))

    CnH2n+2

Show Answer
Answer: ((a))

CnHn

42

Which of the following options must be DISABLED before manually setting the date and time in Windows?

  1. ((a))

    Enable multiple clocks

  2. ((b))

    Set time automatically

  3. ((c))

    Night Light

  4. ((d))

    Set time zone globally

Show Answer
Answer: ((a))

Enable multiple clocks

43

The Mappila Uprisings of the 19th century occurred mainly in which region of India?

  1. ((a))

    Malabar region of Kerala

  2. ((b))

    Coromandel Coast of Tamil Nadu

  3. ((c))

    Sunderbans region of West Bengal

  4. ((d))

    Konkan region of Maharashtra

Show Answer
Answer: ((a))

Malabar region of Kerala

44

Biomedical waste handlers in a hospital are at risk of occupational hazards. The most effective way to protect them from exposure to infectious materials is:

  1. ((a))

    Segregation of waste into color-coded bins

  2. ((b))

    Use of protective equipment and safe handling

  3. ((c))

    Vaccination against common infections

  4. ((d))

    Regular medical check-ups

Show Answer
Answer: ((a))

Segregation of waste into color-coded bins

45

Which of the following is a primary mission under India's National Action Plan on Climate Change (NAPCC)?

  1. ((a))

    National Nutrition Mission

  2. ((b))

    National Solar Mission

  3. ((c))

    National Rural Livelihood Mission

  4. ((d))

    National Highway Development Project

Show Answer
Answer: ((a))

National Nutrition Mission

46

The term 'smog' is a combination of ____________.

  1. ((a))

    Fog and clouds

  2. ((b))

    Smoke and haze

  3. ((c))

    Smoke and fog

  4. ((d))

    Smog and mist

Show Answer
Answer: ((a))

Fog and clouds

47

Match the following columns.

Pardoning powerFunction
1. Commutationa. Removes both sentence and the conviction.
2. Reprieveb. Lesser sentence than originally given, in special cases.
3. Respitec. Reducing the period of sentence without changing the character of the sentence.
4. Remissiond. Temporary stay on the execution of a sentence.
5. Pardone. Substitution of one form of punishment to a lighter one.
  1. ((a))

    1-e, 2-d, 3-b, 4-c, 5-a

  2. ((b))

    1-c, 2-e, 3-b, 4-a, 5-d

  3. ((c))

    1-d, 2-b, 3-e, 4-c, 5-a

  4. ((d))

    1-a, 2-c, 3-d, 4-e, 5-b

Show Answer
Answer: ((a))

1-e, 2-d, 3-b, 4-c, 5-a

48

Which of the following indicators is NOT typically used to measure sustainable development?

  1. ((a))

    Human Development Index (HDI)

  2. ((b))

    Gross Domestic Product (GDP) growth rate

  3. ((c))

    Biocapacity

  4. ((d))

    Ecological Footprint

Show Answer
Answer: ((a))

Human Development Index (HDI)

49

A factory plans to install a powerful electromagnet for lifting metal scraps. To maximize the magnetic field strength around the coil, which of the following combinations would be most effective?

  1. ((a))

    Using a copper core, increasing coil turns, and lowering current

  2. ((b))

    Using an air core, decreasing coil turns, and keeping current constant

  3. ((c))

    Using a steel core, decreasing coil turns, and lowering current

  4. ((d))

    Using a soft iron core, increasing coil turns, and increasing current through the coil

Show Answer
Answer: ((a))

Using a copper core, increasing coil turns, and lowering current

50

You want to automatically advance slides with narration and animations during a presentation. Which MS PowerPoint feature should you use to achieve this?

  1. ((a))

    Action Buttons

  2. ((b))

    Slide Sorter

  3. ((c))

    Rehearse Timings

  4. ((d))

    Presenter View

Show Answer
Answer: ((a))

Action Buttons

Technical Abilities (100 questions)

51

A low demand factor in an electrical installation indicates that:

  1. ((a))

    Connected electrical load is much greater than maximum power demand

  2. ((b))

    Maximum electrical demand exceeds total connected electrical load capacity

  3. ((c))

    Average electrical load remains equal to maximum system demand continuously

  4. ((d))

    Individual consumer demands occur simultaneously during system operation

Show Answer
Answer: ((a))

Connected electrical load is much greater than maximum power demand

52

A limitation of Buchholz relay protection is:

  1. ((a))

    Detection of incipient faults inside oil immersed transformers effectively

  2. ((b))

    Fast isolation of internal transformer faults during abnormal conditions

  3. ((c))

    Automatic detection of gas accumulation inside transformer oil systems

  4. ((d))

    Operation possible only in transformers provided with conservator tanks

Show Answer
Answer: ((a))

Detection of incipient faults inside oil immersed transformers effectively

53

Which point or region represents the Pull-out Torque in the shown torque-speed characteristic of a 3-phase induction motor?

  1. ((a))

    Point c

  2. ((b))

    Anywhere between point a and b

  3. ((c))

    Point b

  4. ((d))

    Point a

Show Answer
Answer: ((a))

Point c

54

In seam welding, the electrodes are made of _______.

  1. ((a))

    copper alloys

  2. ((b))

    aluminium

  3. ((c))

    brass

  4. ((d))

    tungsten

Show Answer
Answer: ((a))

copper alloys

55

Where is the shading coil placed in a shaded-pole motor?

  1. ((a))

    On the motor bearings

  2. ((b))

    On the rotor shaft

  3. ((c))

    On the air-gap surface only

  4. ((d))

    On a portion of the stator pole

Show Answer
Answer: ((a))

On the motor bearings

56

Which of the following statements about the atomic hydrogen arc welding process is correct?

  1. ((a))

    It employs two non-consumable tungsten electrodes to create an arc in a hydrogen atmosphere.

  2. ((b))

    It requires two non-consumable tungsten electrodes and an oxygen-rich atmosphere.

  3. ((c))

    It utilizes a single carbon electrode to generate heat in hydrogen atmosphere.

  4. ((d))

    It works with a consumable iron electrode in a hydrogen atmosphere.

Show Answer
Answer: ((a))

It employs two non-consumable tungsten electrodes to create an arc in a hydrogen atmosphere.

57

The curve obtained in the input characteristics of a BJT in common-emitter (CE) configuration is _______.

  1. ((a))

    Similar to a reverse breakdown curve

  2. ((b))

    A horizontal straight line

  3. ((c))

    Linear for all voltages

  4. ((d))

    Similar to a forward diode curve

Show Answer
Answer: ((a))

Similar to a reverse breakdown curve

58

The output of an alternator is taken from the:

  1. ((a))

    Commutator

  2. ((b))

    Stator winding

  3. ((c))

    Field winding

  4. ((d))

    Rotor winding

Show Answer
Answer: ((a))

Commutator

59

A 12μF capacitor and a 4μF capacitor are connected in series. The ratio of voltages across them will be:

  1. ((a))

    3:1

  2. ((b))

    4:1

  3. ((c))

    1:3

  4. ((d))

    1:4

Show Answer
Answer: ((a))

3:1

60

Three impedances, each of (3−4j) Ω, are connected in delta to a 200 V, three-phase, 50 Hz balanced supply. What are the values of line current and phase current, respectively, in the delta-connected load?

  1. ((a))

    40√3 A and 40 A

  2. ((b))

    40 A and 40√3 A

  3. ((c))

    40 A and 40 A

  4. ((d))

    40√3 A and 40√3 A

Show Answer
Answer: ((a))

40√3 A and 40 A

61

Identify the correct equation for controlling torque (Tc) in a spring-controlled moving iron instrument, where K is the spring constant and θ is the deflection angle.

  1. ((a))

    Tc = K + θ

  2. ((b))

    TC = Kθ

  3. ((c))

    TC = K - θ

  4. ((d))

    TC = Kθ\frac{K}{θ}

Show Answer
Answer: ((a))

Tc = K + θ

62

A Squirrel cage induction generator operates at __________ speed for electric generation in wind turbines.

  1. ((a))

    variable

  2. ((b))

    constant

  3. ((c))

    slip

  4. ((d))

    negligible

Show Answer
Answer: ((a))

variable

63

A DC shunt motor is initially running at no load. What is the effect on its speed when the load is increased?

  1. ((a))

    The speed remains constant

  2. ((b))

    The speed increases slightly

  3. ((c))

    The speed decreases slightly

  4. ((d))

    The speed decreases significantly

Show Answer
Answer: ((a))

The speed remains constant

64

Which of the following is the main purpose of earth resistance measurement?

  1. ((a))

    Reduce frequency variation

  2. ((b))

    Increase power output

  3. ((c))

    Improve voltage level

  4. ((d))

    Ensure safe dissipation of fault current

Show Answer
Answer: ((a))

Reduce frequency variation

65

In a ring distribution system, what happens when there is a fault in one section?

  1. ((a))

    The receiving end voltage becomes more than the sending end voltage.

  2. ((b))

    The voltage drop increases significantly.

  3. ((c))

    The entire system is shut down.

  4. ((d))

    The power can be supplied through the alternate path.

Show Answer
Answer: ((a))

The receiving end voltage becomes more than the sending end voltage.

66

How is the phase angle between voltage V and total current IS​ in a parallel RLC circuit determined?

  1. ((a))

    From the angle between V and IR

  2. ((b))

    By subtracting IL​ from IC

  3. ((c))

    From the angle between V and the vector sum of IR​, IL​, and IC

  4. ((d))

    By comparing voltage drops across each element

Show Answer
Answer: ((a))

From the angle between V and IR

67

A machine delivers power that is three times its original value, while the duration of operation stays unchanged. How does the work done by the machine change?

  1. ((a))

    It becomes three times larger.

  2. ((b))

    It becomes nine times larger.

  3. ((c))

    It becomes one-third of the original.

  4. ((d))

    It remains unchanged.

Show Answer
Answer: ((a))

It becomes three times larger.

68

If the frequency of an AC source is doubled, the impedance of a pure resistor ____________.

  1. ((a))

    remains unchanged

  2. ((b))

    halves

  3. ((c))

    quadruples

  4. ((d))

    doubles

Show Answer
Answer: ((a))

remains unchanged

69

What is the main purpose of providing a properly installed earthing system in electrical installations?

  1. ((a))

    To increase the insulation resistance of conductors

  2. ((b))

    To reduce the reactance of the line conductors

  3. ((c))

    To improve the power factor of the electrical system

  4. ((d))

    To provide a safe path for leakage and fault currents to earth

Show Answer
Answer: ((a))

To increase the insulation resistance of conductors

70

In the graphical analysis of a FET amplifier, what is the primary purpose of the load line?

  1. ((a))

    To determine the input impedance of the FET

  2. ((b))

    To determine the operating point of the FET

  3. ((c))

    To determine the power gain of the FET

  4. ((d))

    To determine the output impedance of the FET

Show Answer
Answer: ((a))

To determine the input impedance of the FET

71

Which generator in wind turbines uses slip rings and a partially rated converter for variable-speed operation?

  1. ((a))

    squirrel cage induction generator

  2. ((b))

    doubly-fed induction generator

  3. ((c))

    permanent magnet synchronous generator

  4. ((d))

    brushless DC generator

Show Answer
Answer: ((a))

squirrel cage induction generator

72

Three identical capacitors are connected in parallel. If the total charge stored in the system is Q, what is the charge on each individual capacitor?

  1. ((a))

    Q/3

  2. ((b))

    3Q

  3. ((c))

    Q/9

  4. ((d))

    Q

Show Answer
Answer: ((a))

Q/3

73

Which strategy reduces electricity charges under a power factor tariff system for a manufacturing plant with predominantly inductive loads?

  1. ((a))

    Operating all equipment at full load constantly

  2. ((b))

    Increasing lighting hours during low demand periods

  3. ((c))

    Installing capacitors to improve the power factor of inductive loads

  4. ((d))

    Switching to higher voltage transformers without changing load characteristics

Show Answer
Answer: ((a))

Operating all equipment at full load constantly

74

Field failure protection in an alternator is provided to detect:

  1. ((a))

    Variation in illumination intensity inside generator control panels

  2. ((b))

    Reduction in paint thickness of alternator outer protective enclosure

  3. ((c))

    Loss of excitation current in the synchronous generator field winding

  4. ((d))

    Change in colour of lubricating oil storage tank surface coating

Show Answer
Answer: ((a))

Variation in illumination intensity inside generator control panels

75

Which statement correctly explains the principle of direct resistance heating?

  1. ((a))

    Heat is generated by the resistance of the material through which the current flows, and it is applied directly to the heating element

  2. ((b))

    The heating element works by electromagnetic induction

  3. ((c))

    Heat is produced through the conversion of mechanical energy into heat

  4. ((d))

    The process is based on the principle of convective heat transfer

Show Answer
Answer: ((a))

Heat is generated by the resistance of the material through which the current flows, and it is applied directly to the heating element

76

Which consideration is important while deciding the capacity of a power station?

  1. ((a))

    Expected maximum electrical demand and future load growth requirements

  2. ((b))

    Number of ceiling fans installed inside administrative office sections

  3. ((c))

    Shape of fencing structure surrounding the generating station premises

  4. ((d))

    Type of paint applied on generating station external building surfaces

Show Answer
Answer: ((a))

Expected maximum electrical demand and future load growth requirements

77

Which of the following points are True regarding the effect of short-time duty on the size and cost of electric motors?

i) Short-time duty allows use of higher rated motors for short durations.
ii) Motors used for short-time duty are generally smaller for the same load.
iii) Short-time duty increases the need for oversized enclosures.
iv) Cost per kW is lower for motors used in short-time duty.

  1. ((a))

    (i), (iii), and (iv) only

  2. ((b))

    (i) and (iii) only

  3. ((c))

    (ii), (iii), and (iv) only

  4. ((d))

    (i), (ii), and (iv) only

Show Answer
Answer: ((a))

(i), (iii), and (iv) only

78

An oscilloscope displays a measured rise time of 10 ns when observing a fast pulse. If the oscilloscope itself has a specified rise time of 6 ns, then what is the approximate actual rise time of the signal being measured?

  1. ((a))

    4 ns

  2. ((b))

    6 ns

  3. ((c))

    8 ns

  4. ((d))

    12 ns

Show Answer
Answer: ((a))

4 ns

79

In a single-phase parallel RL circuit connected to a single phase AC supply, which of the following is correct?

  1. ((a))

    Current leads voltage

  2. ((b))

    Power factor is leading

  3. ((c))

    Current lags voltage

  4. ((d))

    Power factor is unity

Show Answer
Answer: ((a))

Current leads voltage

80

Concentrating solar technology is a type of solar power technology which:

  1. ((a))

    uses sunlight energy to directly rotate turbines without a heat conversion stage

  2. ((b))

    produces heat from sunlight without using mirrors or optical concentration

  3. ((c))

    directly converts sunlight into electricity using photovoltaic (PV) panels

  4. ((d))

    uses mirrors to focus sunlight, generating heat that drives turbines to produce electricity

Show Answer
Answer: ((a))

uses sunlight energy to directly rotate turbines without a heat conversion stage

81

A room requires an average illuminance of 200 lux over a 60 square meter area. If the total luminous flux emitted by the lamps is 15000 lumens and the utilization factor is 0.8, what is the actual illuminance achieved?

  1. ((a))

    100 lux

  2. ((b))

    200 lux

  3. ((c))

    160 lux

  4. ((d))

    125 lux

Show Answer
Answer: ((a))

100 lux

82

What happens to the magnetic field around a straight current-carrying conductor when the current through it is increased?

  1. ((a))

    Magnetic field strength increases

  2. ((b))

    Magnetic field strength decreases

  3. ((c))

    Magnetic field strength remains the same

  4. ((d))

    Magnetic field disappears

Show Answer
Answer: ((a))

Magnetic field strength increases

83

In a series R-C circuit supplied with sinusoidal AC voltage, the current leads the applied voltage by an angle Ø. Which of the following correctly expresses this phase angle?

  1. ((a))

    tan Ø = RXC\frac{R}{X_C}

  2. ((b))

    tan Ø = XCR

  3. ((c))

    tan Ø = −XCR-\frac{X_C}{R}

  4. ((d))

    tan Ø = −RXC - \frac{R}{X_C}

Show Answer
Answer: ((a))

tan Ø = RXC\frac{R}{X_C}

84

The maximum fault current attained during a short circuit at the instant before the fuse completely interrupts the circuit is called:

  1. ((a))

    Cut-off current

  2. ((b))

    Rated current

  3. ((c))

    Melting current

  4. ((d))

    Breaking capacity

Show Answer
Answer: ((a))

Cut-off current

85

Megger is an instrument used to measure ______.

  1. ((a))

    Current carrier.

  2. ((b))

    Source of e.m.f.

  3. ((c))

    High resistance.

  4. ((d))

    Type of a null detector.

Show Answer
Answer: ((a))

Current carrier.

86

Which of the following is a key maintenance practice for reliable operation of a 3-phase induction motor?

  1. ((a))

    Regular lubrication of bearings and periodic insulation resistance testing.

  2. ((b))

    Increasing slip by intentionally weakening rotor bars.

  3. ((c))

    Short-circuiting the stator windings when the motor is idle.

  4. ((d))

    Running the motor continuously at no-load to avoid heating.

Show Answer
Answer: ((a))

Regular lubrication of bearings and periodic insulation resistance testing.

87

On a CRO screen, a DC voltage causes a vertical deflection of 4 divisions. If the vertical sensitivity is 2 V/div, what is the value of the DC voltage?

  1. ((a))

    4 V

  2. ((b))

    8 V

  3. ((c))

    6 V

  4. ((d))

    2 V

Show Answer
Answer: ((a))

4 V

88

Which of the following statements about damping in moving-iron instruments is correct?

  1. ((a))

    Damping in MI instruments is usually provided by a permanent magnet

  2. ((b))

    Damping in MI instruments is usually provided by air friction

  3. ((c))

    Damping in MI instruments is usually provided by eddy currents in an aluminium disc

  4. ((d))

    Damping in MI instruments is usually not required because the pointer is very light

Show Answer
Answer: ((a))

Damping in MI instruments is usually provided by a permanent magnet

89

In a three-phase induction energy meter, the disc rotates due to the interaction between the magnetic fields produced by:

  1. ((a))

    the shunt coil and the field winding

  2. ((b))

    the pressure and current coils

  3. ((c))

    the mechanical gears and shaft

  4. ((d))

    the current and cooling coils

Show Answer
Answer: ((a))

the shunt coil and the field winding

90

An induction furnace operates at 10 kHz and is used to melt 100 kg of steel. If the efficiency is 60% and the energy required to melt steel is 1500 kWh/ton, what is the minimum energy input needed?

  1. ((a))

    150 kWh

  2. ((b))

    90 kWh

  3. ((c))

    250 kWh

  4. ((d))

    180 kWh

Show Answer
Answer: ((a))

150 kWh

91

For the circuit shown in the figure, the current through the resistor R2 is ___________.

  1. ((a))

    2 mA

  2. ((b))

    1.8 mA

  3. ((c))

    2.8 mA

  4. ((d))

    4 mA

Show Answer
Answer: ((a))

2 mA

92

For supplying a large three-phase load with neutral connection requirement, which transformer connection is generally preferred?

  1. ((a))

    Delta-delta connection for single-phase domestic lighting systems

  2. ((b))

    Star-star connection with neutral grounding arrangement on both sides

  3. ((c))

    Scott connection for operation of balanced three-phase motor loads

  4. ((d))

    Open delta connection for reduction of transformer copper losses

Show Answer
Answer: ((a))

Delta-delta connection for single-phase domestic lighting systems

93

A PNP transistor is fabricated with an increased base doping concentration while keeping all other physical dimensions and doping levels constant. What is the effect on the transistor's performance?

  1. ((a))

    The common-emitter current gain decreases

  2. ((b))

    The emitter injection efficiency increases

  3. ((c))

    The base transport factor increases.

  4. ((d))

    The collector current becomes independent of emitter current

Show Answer
Answer: ((a))

The common-emitter current gain decreases

94

In a three-phase induction motor, the phasor diagram shows an angle between the applied stator voltage and the resulting stator current. This angle primarily indicates:

  1. ((a))

    Rotor frequency

  2. ((b))

    Synchronous speed

  3. ((c))

    Rotor slip

  4. ((d))

    Input power factor

Show Answer
Answer: ((a))

Rotor frequency

95

In a single-phase RL circuit, the RMS voltage across the supply is 100 V, the RMS current is 5 A, and the current lags the voltage by 60°. Determine the apparent power of the circuit.

  1. ((a))

    400 VA

  2. ((b))

    250 VA

  3. ((c))

    500 VA

  4. ((d))

    200 VA

Show Answer
Answer: ((a))

400 VA

96

In a radial distribution system, which factor causes an increase in voltage drop?

  1. ((a))

    Increase in load current

  2. ((b))

    Decrease in distance

  3. ((c))

    Decrease in resistance

  4. ((d))

    Increase in insulation

Show Answer
Answer: ((a))

Increase in load current

97

What is an advantage of a bridge rectifier over a center-tapped full-wave rectifier?

  1. ((a))

    A bridge rectifier produces a higher ripple factor at the output

  2. ((b))

    A bridge rectifier uses only half of the transformer secondary winding

  3. ((c))

    A bridge rectifier can operate using diodes with lower peak inverse voltage rating

  4. ((d))

    A bridge rectifier requires fewer diodes for rectification

Show Answer
Answer: ((a))

A bridge rectifier produces a higher ripple factor at the output

98

In a closed electrical loop supplied by 10 V, two resistors produce voltage drops of 6 V and 4 V, respectively. Which statement correctly expresses Kirchhoff’s Voltage Law for this loop?

  1. ((a))

    The source voltage is greater than the total voltage drop

  2. ((b))

    The current through the two resistors is different

  3. ((c))

    The source voltage is less than the total voltage drop

  4. ((d))

    The algebraic sum of all voltages around the loop is zero

Show Answer
Answer: ((a))

The source voltage is greater than the total voltage drop

99

Which Law illustrates the relationship between induced electromotive force (EMF) and the time variation of magnetic flux in a coil?

  1. ((a))

    Columb's Law

  2. ((b))

    Faraday Law of Induction

  3. ((c))

    Ampere Circuital Law

  4. ((d))

    Lenz's Law

Show Answer
Answer: ((a))

Columb's Law

100

Which method is commonly used to reduce earth resistance in an electrical installation?

  1. ((a))

    Increasing the supply voltage

  2. ((b))

    Increasing the number of earth electrodes

  3. ((c))

    Reducing the size of the earth conductor

  4. ((d))

    Using a higher-rated fuse

Show Answer
Answer: ((a))

Increasing the supply voltage

101

The fundamental operating principle of a transformer is based on:

  1. ((a))

    electromagnetic induction between two electrically isolated coils magnetically coupled through a low-reluctance magnetic circuit

  2. ((b))

    conversion of alternating current (AC) into direct current (DC) via semiconductor devices

  3. ((c))

    mechanical coupling of coils to facilitate energy transfer through physical motion

  4. ((d))

    direct electrical conduction between primary and secondary windings for energy transfer

Show Answer
Answer: ((a))

electromagnetic induction between two electrically isolated coils magnetically coupled through a low-reluctance magnetic circuit

102

At which voltage level are the maximum consumers connected?

  1. ((a))

    secondary distribution level

  2. ((b))

    primary distribution level

  3. ((c))

    secondary transmission level

  4. ((d))

    primary transmission level

Show Answer
Answer: ((a))

secondary distribution level

103

A single-phase preventer continuously monitors and protects preferably which motor against phase failure?

  1. ((a))

    Single phase induction motor

  2. ((b))

    3-phase induction motor

  3. ((c))

    Reluctance motor

  4. ((d))

    DC Motor

Show Answer
Answer: ((a))

Single phase induction motor

104

What does the plant use factor represent?

  1. ((a))

    The ratio of actual energy generated to the product of plant capacity and hours of use

  2. ((b))

    The ratio of actual energy generated to the total installed capacity

  3. ((c))

    The ratio of average load to maximum demand

  4. ((d))

    The ratio of maximum demand to the total installed capacity

Show Answer
Answer: ((a))

The ratio of actual energy generated to the product of plant capacity and hours of use

105

Which among the given statements correctly distinguishes Avalanche breakdown from Zener breakdown in a PN junction diode?

  1. ((a))

    Avalanche breakdown is the predominant mechanism in lightly doped junctions.

  2. ((b))

    Zener breakdown voltage is typically higher than the avalanche breakdown voltage.

  3. ((c))

    Zener breakdown occurs only under forward bias conditions.

  4. ((d))

    Avalanche breakdown does not result in a sharp increase in reverse current.

Show Answer
Answer: ((a))

Avalanche breakdown is the predominant mechanism in lightly doped junctions.

106

A current I flows through a circular loop. If the radius of the loop is reduced to half and the current is doubled, the magnetic field intensity at the center becomes:

  1. ((a))

    Unchanged

  2. ((b))

    Eight times the original value

  3. ((c))

    Four times the original value

  4. ((d))

    Twice the original value

Show Answer
Answer: ((a))

Unchanged

107

What is the primary fuel used in a biomass power plant?

  1. ((a))

    Coal

  2. ((b))

    Natural gas

  3. ((c))

    Uranium

  4. ((d))

    Organic waste materials

Show Answer
Answer: ((a))

Coal

108

A maximum demand tariff is designed to encourage consumers to _________________.

  1. ((a))

    Reduce overall energy consumption

  2. ((b))

    Manage and reduce their peak power demand

  3. ((c))

    Adopt renewable energy sources

  4. ((d))

    Increase energy production

Show Answer
Answer: ((a))

Reduce overall energy consumption

109

In a parallel RC circuit connected to a single-phase AC supply, the correct relationship between the supply voltage and the total circuit current is _________.

  1. ((a))

    Current is in phase with the voltage

  2. ((b))

    Current lags the voltage

  3. ((c))

    Current and voltage are 180° out of phase

  4. ((d))

    Current leads the voltage

Show Answer
Answer: ((a))

Current is in phase with the voltage

110

A 12 V battery is connected in series with two resistors 4 Ω and 6 Ω, forming a closed circuit. What is the Thevenin equivalent resistance across the terminals of the 6 Ω resistor after it is removed?

  1. ((a))

    10 Ω

  2. ((b))

    6 Ω

  3. ((c))

    4 Ω

  4. ((d))

    2 Ω

Show Answer
Answer: ((a))

10 Ω

111

The Norton equivalent of the circuit shown in figure at terminals a-b are __________.

  1. ((a))

    RN = 4Ω, IN = 1 A

  2. ((b))

    RN = 4Ω, IN = 2 A

  3. ((c))

    RN = 25Ω, IN = 1 A

  4. ((d))

    RN = 25Ω, IN = 3 A

Show Answer
Answer: ((a))

RN = 4Ω, IN = 1 A

112

Which set of statements correctly describes the steady state speed-torque characteristics of a three-phase synchronous motor?
i) Runs at constant synchronous speed
ii) Starting torque is zero
iii) Torque increases significantly with slip
iv) Not suitable for variable speed drives
v) Maintains speed under varying loads

  1. ((a))

    (i), (ii), and (v) only

  2. ((b))

    (i), (ii), (iii) and (v) only

  3. ((c))

    (i), (ii), (iii) and (iv) only

  4. ((d))

    (i), (iii), (iv) and (v) only

Show Answer
Answer: ((a))

(i), (ii), and (v) only

113

Which of the following balanced phase-voltage phasor sets represents an abc positive-sequence system?

  1. ((a))

    Va = 0°, Vb = 120°, Vc = -120°

  2. ((b))

    Va = 0°, Vb = 90°, Vc = 180°

  3. ((c))

    Va = 0°, Vb = -90°, Vc = -180°

  4. ((d))

    Va = 0°, Vb = -120°, Vc = 120°

Show Answer
Answer: ((a))

Va = 0°, Vb = 120°, Vc = -120°

114

For accurate measurement of inductors using Hay's bridge, which characteristic should the inductor primarily possess?

  1. ((a))

    High resistance

  2. ((b))

    Low Q-factor

  3. ((c))

    High Q-factor

  4. ((d))

    Medium Q-factor

Show Answer
Answer: ((a))

High resistance

115

Which of the following sets of statements about the causes of errors in current transformers is correct?
i) Leakage reactance in secondary winding contributes to ratio error
ii) High magnetizing current increases phase angle error
iii) Burden with low power factor increases phase angle error
iv) Core saturation reduces both ratio and phase angle errors

  1. ((a))

    (ii) and (iv) only

  2. ((b))

    (iii) and (iv) only

  3. ((c))

    (i) and (iv) only

  4. ((d))

    (i), (ii) and (iii) only

Show Answer
Answer: ((a))

(ii) and (iv) only

116

What does the Reduction Factor in illumination refer to?

  1. ((a))

    The percentage of light lost due to reflection and absorption

  2. ((b))

    The ratio of actual illuminance to theoretical illuminance

  3. ((c))

    The ratio of the illumination at a given point to the initial illumination

  4. ((d))

    The ratio of total luminous flux to the consumed electrical power

Show Answer
Answer: ((a))

The percentage of light lost due to reflection and absorption

117

Which of the following devices provide rapid fault current interruption independently in a high-voltage power distribution system?

  1. ((a))

    Contactor

  2. ((b))

    Linear coupler

  3. ((c))

    HRC fuse

  4. ((d))

    Isolator

Show Answer
Answer: ((a))

Contactor

118

A protective device with high rupturing capacity can:

  1. ((a))

    Improve voltage regulation of transformers during overload conditions

  2. ((b))

    Increase insulation resistance during normal system operating conditions

  3. ((c))

    Reduce transmission line inductance during balanced load operation only

  4. ((d))

    Safely interrupt heavy fault currents without equipment damage occurrence

Show Answer
Answer: ((a))

Improve voltage regulation of transformers during overload conditions

119

A three-phase slip ring induction motor is preferred over a squirrel cage induction motor for which of the following application scenarios?

  1. ((a))

    When highest efficiency is the only concern

  2. ((b))

    When constant speed under all load conditions is needed

  3. ((c))

    When variable speed and high starting torque are required

  4. ((d))

    When reduced maintenance is the top priority

Show Answer
Answer: ((a))

When highest efficiency is the only concern

120

The speed of a synchronous motor depends on:

  1. ((a))

    Field resistance

  2. ((b))

    Supply frequency

  3. ((c))

    Armature current

  4. ((d))

    Load only

Show Answer
Answer: ((a))

Field resistance

121

Select the option that is correct regarding the following two statements labelled Assertion (A) and Reason (R).

Assertion (A): Three-phase auto-transformers are smaller and lighter than equivalent three-phase two-winding transformers.
Reason (R): Auto-transformers use fewer windings and a smaller core.

  1. ((a))

    Both A and R are true, and R is the correct explanation of A.

  2. ((b))

    A is true, but R is false.

  3. ((c))

    A is false, but R is true.

  4. ((d))

    Both A and R are true, but R is not the correct explanation of A.

Show Answer
Answer: ((a))

Both A and R are true, and R is the correct explanation of A.

122

Which statement about magnetic flux is false?

  1. ((a))

    Magnetic flux density unit is Tesla or weber per meter square (Wb/m2).

  2. ((b))

    Magnetic flux density is the magnetic flux passing through per unit cross-section area.

  3. ((c))

    Magnetic flux does not have any SI unit.

  4. ((d))

    Magnetic flux is analogous to current in electric circuit.

Show Answer
Answer: ((a))

Magnetic flux density unit is Tesla or weber per meter square (Wb/m2).

123

Anderson’s bridge belongs to which category of measuring circuits?

  1. ((a))

    DC potentiometer circuit

  2. ((b))

    AC bridge for inductance measurement

  3. ((c))

    DC bridge for resistance measurement

  4. ((d))

    Resonance circuit for frequency measurement

Show Answer
Answer: ((a))

DC potentiometer circuit

124

Which combination of the following statements about direct resistance heating are correct?
i) The process requires the charge to be electrically conductive.
ii) Electrodes are placed in direct contact with the charge.
iii) Heat is generated by induced eddy currents in the charge.
iv) The charge does not form part of the electric circuit.

  1. ((a))

    (i) and (iv) only

  2. ((b))

    (ii) and (iii) only

  3. ((c))

    (iii) and (iv) only

  4. ((d))

    (i) and (ii) only

Show Answer
Answer: ((a))

(i) and (iv) only

125

Determine whether x(t)=sin(3t) + sin(5t) is periodic. If yes, find its fundamental period.

  1. ((a))

    T=π

  2. ((b))

    T=2π

  3. ((c))

    T=π/5

  4. ((d))

    Non-periodic

Show Answer
Answer: ((a))

T=π

126

In the given circuit R1= 6Ω, R2= 4Ω and R3= 3Ω. The voltage sources are V1 = 21V and V2 = 5V. Determine the currents flowing through R₁ and R₂, respectively.

  1. ((a))

    2A and 6A

  2. ((b))

    4A and 6A

  3. ((c))

    3A and 2A

  4. ((d))

    2A and 3A

Show Answer
Answer: ((a))

2A and 6A

127

What is the main objective of backup protection in a power system?

  1. ((a))

    To detect minor disturbances in voltage

  2. ((b))

    To increase the complexity of the system

  3. ((c))

    To isolate faults if primary protection fails

  4. ((d))

    To operate faster than primary protection

Show Answer
Answer: ((a))

To detect minor disturbances in voltage

128

The Thevenin equivalent voltage at terminals a-b is _________________.

  1. ((a))

    10 V

  2. ((b))

    9 V

  3. ((c))

    12 V

  4. ((d))

    6 V

Show Answer
Answer: ((a))

10 V

129

Which type of magnetic material loses its magnetism immediately after the removal of the magnetic field?

  1. ((a))

    Diamagnetic

  2. ((b))

    Ferrimagnetic

  3. ((c))

    Ferromagnetic

  4. ((d))

    Paramagnetic

Show Answer
Answer: ((a))

Diamagnetic

130

Why does a squirrel cage induction motor not develop maximum starting torque?

  1. ((a))

    Slip is less than unity at starting

  2. ((b))

    Rotor reactance is zero at starting

  3. ((c))

    Rotor resistance is fixed and low

  4. ((d))

    Rotor resistance can be externally varied at starting

Show Answer
Answer: ((a))

Slip is less than unity at starting

131

An underground cable used in power systems should possess which important requirement?

  1. ((a))

    High insulation resistance and adequate mechanical strength properties

  2. ((b))

    Variable conductor diameter during balanced load operating conditions

  3. ((c))

    Low melting point of conductor material during fault conditions

  4. ((d))

    High magnetic saturation capability inside cable conductor arrangements only

Show Answer
Answer: ((a))

High insulation resistance and adequate mechanical strength properties

132

What is the main disadvantage of a half-wave rectifier?

  1. ((a))

    Utilizes only one half-cycle

  2. ((b))

    High cost

  3. ((c))

    Requires center-tap transformer

  4. ((d))

    Ripple frequency equal to supply frequency

Show Answer
Answer: ((a))

Utilizes only one half-cycle

133

Which of the following is used to join two cable conductors?

  1. ((a))

    Cable marking

  2. ((b))

    Insulation taping

  3. ((c))

    Surface coating

  4. ((d))

    Splicing

Show Answer
Answer: ((a))

Cable marking

134

In a DC generator, the magnitude of induced EMF is directly proportional to:

  1. ((a))

    the armature resistance

  2. ((b))

    the product of flux per pole and speed

  3. ((c))

    the inverse of number of conductors

  4. ((d))

    the square of flux per pole

Show Answer
Answer: ((a))

the armature resistance

135

Retentivity in a B-H curve indicates:

  1. ((a))

    Maximum field strength

  2. ((b))

    Reverse magnetic field required to reduce flux density to zero

  3. ((c))

    Magnetic flux density left after removing the external magnetizing force

  4. ((d))

    Resistance to demagnetization

Show Answer
Answer: ((a))

Maximum field strength

136

A power factor tariff is introduced in energy billing to encourage consumers to ________________.

  1. ((a))

    Receive discounts based only on total energy consumption

  2. ((b))

    Pay a fixed electricity charge regardless of usage pattern

  3. ((c))

    Improve their power factor for more efficient use of electrical power

  4. ((d))

    Reduce electricity consumption during peak hours

Show Answer
Answer: ((a))

Receive discounts based only on total energy consumption

137

In a buck-boost converter, how does the inductor contribute to the inversion of the input voltage polarity while regulating the output voltage?

  1. ((a))

    The inductor filters out high-frequency noise from the input supply.

  2. ((b))

    The inductor provides a low-impedance path for the return current.

  3. ((c))

    The inductor stores energy from the input voltage and releases it in the opposite polarity during the 'off' phase of the switch.

  4. ((d))

    The inductor acts as a transformer to invert the voltage polarity.

Show Answer
Answer: ((a))

The inductor filters out high-frequency noise from the input supply.

138

Which modification in an earthing system most directly reduces earth resistance by improving the contact area between the electrode and surrounding soil?

  1. ((a))

    Increasing the rating of the protective fuse

  2. ((b))

    Connecting the earth conductor to the neutral wire only

  3. ((c))

    Using a higher supply voltage in the installation

  4. ((d))

    Increasing the effective contact area by using multiple or larger earth electrodes

Show Answer
Answer: ((a))

Increasing the rating of the protective fuse

139

Two inductors of 8 H and 2 H connected in series opposing with mutual inductance of 1 H will have equivalent:

  1. ((a))

    11 H

  2. ((b))

    8 H

  3. ((c))

    5 H

  4. ((d))

    9 H

Show Answer
Answer: ((a))

11 H

140

When an alternator operates at unity power factor, the armature current:

  1. ((a))

    lags terminal voltage

  2. ((b))

    is in phase with terminal voltage

  3. ((c))

    leads terminal voltage

  4. ((d))

    is opposite to terminal voltage

Show Answer
Answer: ((a))

lags terminal voltage

141

Consider the following statements about torque in synchronous motors.

I. The torque in a synchronous motor is produced only when the rotor is locked into synchronism.
II. The torque is directly proportional to the sine of the load angle (δ).
III. Synchronous motor develops starting torque proportional to the power input.
IV. Maximum torque occurs at δ = 180°.

Which of the above statements are correct?

  1. ((a))

    Statements II, III & IV only

  2. ((b))

    Statements I, II & III only

  3. ((c))

    Statements II & IV only

  4. ((d))

    Statements I & II only

Show Answer
Answer: ((a))

Statements II, III & IV only

142

Why are instrument transformers used with a wattmeter for high-power AC measurements?

  1. ((a))

    To eliminate the need for a pressure coil in the wattmeter

  2. ((b))

    To reduce the frequency of the measured circuit

  3. ((c))

    To convert AC power into DC power

  4. ((d))

    To extend the current and voltage range of the wattmeter safely

Show Answer
Answer: ((a))

To eliminate the need for a pressure coil in the wattmeter

143

Which crystal structure is specifically associated with ferrite iron (α-iron), a ferromagnetic material?

  1. ((a))

    Face-centered cubic (FCC)

  2. ((b))

    Body-centered cubic (BCC)

  3. ((c))

    Diamond cubic

  4. ((d))

    Hexagonal close-packed (HCP)

Show Answer
Answer: ((a))

Face-centered cubic (FCC)

144

What is the purpose of a Buchholz relay in transformer protection?

  1. ((a))

    To measure temperature rise

  2. ((b))

    To measure core flux

  3. ((c))

    To detect overvoltage

  4. ((d))

    To detect internal faults such as short circuits and arcing in oil

Show Answer
Answer: ((a))

To measure temperature rise

145

In a properly biased PNP transistor operating in active region, the emitter terminal is _______.

  1. ((a))

    equal in potential to the base

  2. ((b))

    more negative than the collector

  3. ((c))

    more positive than the base

  4. ((d))

    grounded permanently

Show Answer
Answer: ((a))

equal in potential to the base

146

A PNP transistor is operating in active region. If the emitter voltage decreases such that the emitter becomes less positive than the base while the biasing condition of the collector-base junction remains unchanged, the transistor will enter _______.

  1. ((a))

    Active region with higher gain

  2. ((b))

    Reverse active region

  3. ((c))

    Cut-off region

  4. ((d))

    Saturation region

Show Answer
Answer: ((a))

Active region with higher gain

147

Protection of transmission lines using differential pilot wire protection provides:

  1. ((a))

    Increasing transmission conductor diameter during overload conditions

  2. ((b))

    Fast and selective protection of short transmission feeder sections

  3. ((c))

    Reducing transmission line inductance under balanced operating conditions only

  4. ((d))

    Improving illumination level inside substation control room sections

Show Answer
Answer: ((a))

Increasing transmission conductor diameter during overload conditions

148

The hypotenuse of the power triangle represents which type of power?

  1. ((a))

    Reactive power

  2. ((b))

    Apparent power

  3. ((c))

    Active power

  4. ((d))

    Power factor

Show Answer
Answer: ((a))

Reactive power

149

The tapping in an auto transformer is used to:

  1. ((a))

    separate windings

  2. ((b))

    reduce insulation

  3. ((c))

    increase magnetic losses

  4. ((d))

    regulate voltage output

Show Answer
Answer: ((a))

separate windings

150

What is a typical starting torque characteristic of a shaded pole induction motor?

  1. ((a))

    Low starting torque and low efficiency

  2. ((b))

    Low starting torque and high efficiency

  3. ((c))

    High starting torque and low efficiency

  4. ((d))

    High starting torque and high efficiency

Show Answer
Answer: ((a))

Low starting torque and low efficiency

Attempt this paper under real exam conditions

Timed interface, section switching, instant scoring, and question-by-question analytics — free.

Start Timed Attempt