Held in 2025
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Take this paper as a timed mock test. Review your answers after you submit.
Read the paper at your pace. Open an explanation when you need it.
Which of the following is an example of a chemical change?
Dissolution of sugar in water
Curdling of milk
Freezing of water
Tearing of paper
Correct answer
Dissolution of sugar in water
If the area of contact increases while keeping the thrust constant, the pressure will __________.
increase
remain the same
first increase, then decrease
decrease
Correct answer
increase
What happens when you use the 'Sort A to Z' option on a column containing text?
The text remains unchanged.
The text is sorted alphabetically from A to Z.
The text is sorted from Z to A.
The text is converted into numbers.
Correct answer
The text remains unchanged.
The method of storage of nuclear wastes is to be done in _______.
bottles
dustbins
open containers
shielded containers
Correct answer
bottles
When were the 38th National Games held in Uttarakhand?
January 15 - 30, 2025
January 28 - February 14, 2025
February 10 - 25, 2025
February 1 - 20, 2025
Correct answer
January 15 - 30, 2025
In December 2024, Jasprit Bumrah became the fastest Indian bowler to reach 200 Test wickets during which of the following series/tournament?
Border-Gavaskar Trophy
India vs England Test Series
Asia Cup
India vs New Zealand Test Series
Correct answer
Border-Gavaskar Trophy
The Railways Employment of Members of the Armed Forces Act was passed in which of the following years?
1951
1962
1965
1957
Correct answer
1951
Where is the magnetic field strength maximum around a magnet?
Equidistant from the poles
At the poles of the magnet
At infinity
At the centre of the magnet
Correct answer
Equidistant from the poles
In an experiment, 25 g of reactant A reacts with 35 g of reactant B to form 50 g of product C and some amount of product D. What is the mass of product D?
35 g
25 g
60 g
10 g
Correct answer
35 g
Which of the following is a zero waste procedure?
Pest management
Organic farming
Integrated organic farming
Inorganic farming
Correct answer
Pest management
The greenhouse gas that is known to contribute the least amount to global warming is ___________.
carbon dioxide
methane
CFCs
nitrous oxide
Correct answer
carbon dioxide
Two objects of masses 80 kg and 250 kg are placed 200 m apart. What is the gravitational force between them? (G = 6.7 × 10-11 N.m2/kg2)
6.35 × 10-11 N
5.75 × 10-11 N
4.50 × 10-11 N
3.35 × 10-11 N
Correct answer
6.35 × 10-11 N
Which of the following is a string instrument?
Tabla
Sitar
Flute
Shehnai
Correct answer
Tabla
The speed of a wave is given by which of the following formulas?
Speed = Time × Frequency
Speed = Frequency × Amplitude
Speed = Amplitude × Wavelength
Speed = Frequency × Wavelength
Correct answer
Speed = Time × Frequency
The loss of forests, which is remarkably seen in the tropical areas of India, is around __________.
40%
30%
20%
10%
Correct answer
40%
As per Article 78, it is the duty of the Prime Minister to communicate all decisions of the Council of Ministers to whom?
Chief Justice of India
Speaker of Lok Sabha
President
Vice President
Correct answer
Chief Justice of India
What is the purpose of the 'BCC' field in an email?
It hides recipients from each other.
It deletes an email after it is read.
It allows recipients to see each others' addresses.
It marks an email as urgent.
Correct answer
It hides recipients from each other.
_____ is the most efficient method used for the disposal of hospital-generated waste.
Sanitary landfills
Incinerator
Furnace
Open dumps
Correct answer
Sanitary landfills
Under the Delhi Sultanate what was the name of the state laws that grew under the monarchy, even if they violated the Shari’at?
Farman
Iqta
Zawabit
Fatwas
Correct answer
Farman
Which statement correctly explains why liquids can flow?
Liquids have no intermolecular forces.
Liquids have loosely packed molecules that slide past each other.
Liquids do not have kinetic energy.
Liquid molecules move randomly without any restriction.
Correct answer
Liquids have no intermolecular forces.
If three resistors of 15 Ω, 35 Ω and 50 Ω are connected in series to a 25-V battery, what is the current flowing in the circuit?
4 A
1.5 A
0.25 A
2.88 A
Correct answer
4 A
What is the function of the Linux Shell?
To directly manage hardware resources
To execute user commands and act as an interface between the user and the kernel
To store user data
To create and delete partitions
Correct answer
To directly manage hardware resources
Which of the following economic estimators provided estimates of India’s national and per capita income during the colonial period?
Adam Smith
John Maynard Keynes
VKRV Rao
Karl Marx
Correct answer
Adam Smith
Which of the following is NOT an example of an agrochemical?
Pesticides
Fungicides
Herbicides
Biogas
Correct answer
Pesticides
What is the typical range of a Local Area Network (LAN)?
Up to 10 km
Up to 5 km
Up to 1 km
More than 50 km
Correct answer
Up to 10 km
According to the Tendulkar methodology, what was the estimated national poverty line for rural areas in 2011-12?
₹816 per month
₹1,200 per month
₹1,000 per month
₹512 per month
Correct answer
₹816 per month
What are the sand dunes commonly found in the Indian Desert called?
Barchans
Loess
Moraines
Cirques
Correct answer
Barchans
If the mass of an object is 74.5 kg, what is its approximate weight on Earth? (Take g = 9.8 m/s2)
730 N
447 N
7.6 N
74.5 N
Correct answer
730 N
The Montreal Protocol came into force in the year ________.
1986
1989
1990
1992
Correct answer
1986
Which property of solids allows them to be compressed the least compared to liquids and gases?
High intermolecular spaces
The ability to diffuse into other solids
Strong intermolecular forces and close packing of particles
High kinetic energy of particles
Correct answer
High intermolecular spaces
Which of the following best describes a heterogeneous mixture?
It has a uniform composition.
The components cannot be separated.
The composition varies throughout the mixture.
It contains only one phase
Correct answer
It has a uniform composition.
A student calculates the formula unit mass of calcium fluoride (CaF2). If the atomic masses of Ca and F are 40 u and 19 u, respectively, what is the correct formula unit mass?
97 u
78 u
100 u
59 u
Correct answer
97 u
The area termed as the ozone hole is known to mainly develop over ______.
India
Africa
Antartica
America
Correct answer
India
Who among the following is NOT appointed by the President of India?
Governors of States
Vice President
Chief Election Commissioner
Comptroller and Auditor General
Correct answer
Governors of States
Which dynasty was overthrown by Chandragupta Maurya to establish the Mauryan Empire?
Gupta Dynasty
Kushan Dynasty
Shunga Dynasty
Nanda Dynasty
Correct answer
Gupta Dynasty
Which of the following is NOT an example of system software?
macOS
Linux
Microsoft Word
Windows 10
Correct answer
macOS
Which of the following metals is placed above aluminium and zinc in the reactivity series?
Magnesium
Iron
Copper
Carbon
Correct answer
Magnesium
Who among the following won the gold medal in the women's high jump event at the National Games in February 2025?
Vithya Ramraj
Pooja Singh
Abhinaya Shetty
Swapna Barman
Correct answer
Vithya Ramraj
Which of the following is an effective way to prevent rancidity in packaged food?
Adding antioxidants
Increasing moisture content
Keeping it in direct sunlight
Storing in a warm place
Correct answer
Adding antioxidants
The Punjab Plain is formed by which river system?
Indus and its tributaries
Narmada and its tributaries
Ganga and its tributaries
Brahmaputra and its tributaries
Correct answer
Indus and its tributaries
An object is placed 25 cm in front of a convex lens with a focal length of 15 cm. What is the magnification produced by the lens?
M = −2.5
M = 1.5
M = 2.5
M = −1.5
Correct answer
M = −2.5
The effect of particulate matter which is a common air pollutant is maximally seen on the _______.
intestines
kidneys
lungs
liver
Correct answer
intestines
The Indian Desert lies towards the western margins of which mountain range?
Western Ghats
Satpura Hills
Vindhya Hills
Aravali Hills
Correct answer
Western Ghats
What is the primary goal of application security?
To reduce the size of application files
To enhance the graphical user interface of applications
To protect applications from security threats by identifying and fixing vulnerabilities
To increase the execution speed of applications
Correct answer
To reduce the size of application files
Which of the following is an example of database management software?
MS Paint
Notepad
PowerPoint
Microsoft Access
Correct answer
MS Paint
Which of the following is NOT a file management task?
Creating files
Browsing the internet
Renaming files
Deleting files
Correct answer
Creating files
Which mouse pointer appears when adjusting column width / cell width in a table?
↔ (Horizontal double-headed arrow)
↕ (Vertical double-headed arrow)
I-beam (Text cursor)
Hand cursor
Correct answer
↔ (Horizontal double-headed arrow)
The melting of snow and ice caps from the polar regions is responsible for ________.
condensation
the rise in sea levels
the decline in sea levels
rainfall
Correct answer
condensation
In September 2024, which of the following Indian institutions was designated as the Thematic Hub for Quantum Computing under the National Quantum Mission?
Indian Institute of Technology Madras
Indian Institute of Technology Kanpur
Indian Institute of Technology Gandhinagar
Indian Institute of Science Bengaluru
Correct answer
Indian Institute of Technology Madras
Which of the following is an example of a WAN?
A Bluetooth connection between a phone and a laptop
A home Wi-Fi network
The internet
A university campus network
Correct answer
A Bluetooth connection between a phone and a laptop
The load on a power plant on a typical day is as given in the following table.
| Time | 0-6 | 6-9 | 9-18 | 18-22 | 22-24 |
|---|---|---|---|---|---|
| Load (MW) | 2 | 40 | 80 | 100 | 25 |
Find the load factor of the plant.
60%
40%
50%
80%
Correct answer
60%
For a P-N junction diode, thermal equilibrium occurs when _________.
force produced by the electric field is always zero
force produced by the electric field and the 'force' produced by the density gradient exactly balance
force produced by the electric field is greater than the 'force' produced by the density gradient
force produced by the electric field is less than the 'force' produced by the density gradient
Correct answer
force produced by the electric field is always zero
The unit of magnetising force is:
weber/metre2
joule/weber
ampere/metre
henry/metre
Correct answer
weber/metre2
A 10-ohm resistor is connected across a 12-V battery. How much current flows through the resistor?
0.8 A
2.0 A
120 A
1.2 A
Correct answer
0.8 A
In the right-hand rule, the thumb points in the direction of ______________.
lines of flux
current
motion
magnetic field
Correct answer
lines of flux
What is the modified starter called when the holding coil circuit is made independent of the field circuit?
2-point starter
3-point starter
4-point starter
5-point starter
Correct answer
2-point starter
Calculate the ripple factor (in percentage) if the dc and ac voltmeter used to measure the output signal from a rectifier circuit gives the readings of 25 V dc and 1.5 V rms.
17%
34%
25%
6%
Correct answer
17%
What is the primary mechanism of current conduction in a Bipolar Junction Transistor (BJT)?
Electromagnetic induction
Majority carrier conduction
Minority carrier conduction
Electrostatic induction
Correct answer
Electromagnetic induction
The real part of admittance in phasor form is called _______ and the imaginary part is called _________.
impedance; reactance
reactance; conductance
resistance; reactance
conductance; susceptance
Correct answer
impedance; reactance
How does a servo motor control its shaft position?
By adjusting the frequency of the AC supply
By changing stator winding resistance
By varying input voltage
Using pulse-width modulation (PWM) signals
Correct answer
By adjusting the frequency of the AC supply
Applications of synchronous reluctance motors include:
I. Industrial compressors for improved energy efficiency.
II. Electric trains for high starting torque capabilities.
III. Solar-powered water pumps for reliability.
IV. Consumer drones for compact size.
Statement II and III only correct.
Statement II and IV only correct.
Statement I and IV only correct.
Statement I and III only correct.
Correct answer
Statement II and III only correct.
What is the primary purpose of estimation in electrical installations?
To ensure compliance with aesthetic design standards
To focus solely on the operation and maintenance of electrical systems
To replace the need for protective devices in electrical systems
To predict the cost, materials and time required for completing an electrical project
Correct answer
To ensure compliance with aesthetic design standards
Which of the following factors most significantly affects the efficiency of a Fresnel reflector in a solar concentrator system?
The number of mirror strips and their alignment accuracy
The temperature of the environment
The colour of the reflector material
The wavelength of incident light
Correct answer
The number of mirror strips and their alignment accuracy
The unit of reluctance is _______.
Weber
Ampere-turn/Weber
Henry
Ampere/Weber
Correct answer
Weber
The back-EMF waveform of a BLDC motor is typically ______.
Square
Trapezoidal
Triangular
Sinusoidal
Correct answer
Square
Why is WRIG preferred over Squirrel Cage Induction Generator (SCIG) in some wind turbines?
WRIG does not require maintenance due to the absence of slip rings
WRIG allows external rotor resistance control, enabling better efficiency and power factor control
WRIG works only with constant-speed wind turbines
WRIG has no moving parts, making it more durable
Correct answer
WRIG does not require maintenance due to the absence of slip rings
Which of the following statements describe applications of three-phase squirrel cage induction motors?
I. Driving escalators and elevators.
II. Powering household refrigerators.
III. Operating centrifugal pumps in industrial plants.
IV. Used in electric vehicles for propulsion.
II, and IV only correct
I, II, and III only correct
I and III only correct
I and IV only correct
Correct answer
II, and IV only correct
In a transmission line with supports at different heights, the lowest point of the conductor is located:
exactly at the midpoint of the span
closer to the lower support
closer to the higher support
at the higher support
Correct answer
exactly at the midpoint of the span
Which system is responsible for delivering electricity from local transformers to endusers?
Generation system
Primary distribution system
Transmission system
Secondary distribution system
Correct answer
Generation system
Which of the following is NOT an example of solid biomass?
Natural gas
Firewood
Sugarcane bagasse
Wood pellets
Correct answer
Natural gas
Which of the following statements is/are correct?
Statement 1: A single large generating unit requires periodic maintenance, which may lead to a complete shutdown of power supply.
Statement 2: In a multi-unit system, maintenance can be scheduled without completely interrupting power generation.
Only Statement 1
Only Statement 2
Neither Statement 1 nor Statement 2
Both Statement 1 and Statement 2
Correct answer
Only Statement 1
If R is the resistance of an R-L series circuit and reactive inductance is XL , then the power factor of a series R-L circuit is given by _______.
\(\rm \cos \theta=\frac{X_L}{Z}\)
\(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\)
\(\rm \cos \theta=\frac{Z}{R}\)
\(\rm \cos \theta=\frac{R}{Z}\)
\(\rm \cos \theta=\frac{R}{X_L}\)
Correct answer
\(\rm \cos \theta=\frac{X_L}{Z}\)
If a straight long conductor is carrying current, the magnetic lines of force will be:
only anticlockwise around the conductor
only clockwise around the conductor
concentric circles clockwise/anticlockwise around the conductor
in straight line across the conductor
Correct answer
only anticlockwise around the conductor
The material used in the armature core of a DC generator is typically:
silicon steel
copper
aluminium
plastic
Correct answer
silicon steel
Consider three doping concentration levels represented by i) n++, ii) p+ and iii) n. Relate the corresponding doping concentration with emitter, base and collector regions for a NPN transistor
i. n++ corresponds to base, ii. p+ corresponds to collector and, iii. n for emitter
i. n++ corresponds to emitter, ii. p+ corresponds to base and, iii. n for collector
i. n++ corresponds to collector, ii. p+ corresponds to base and, iii. n for emitter
i. n++ corresponds to base, ii. p+ corresponds to emitter and, iii. n for collector
Correct answer
i. n++ corresponds to base, ii. p+ corresponds to collector and, iii. n for emitter
The EMF generated in a rotating coil within a uniform magnetic field is maximum when _________.
the coil is parallel to the magnetic field
the rate of change of flux is minimum
the current is maximum
the coil is perpendicular to the magnetic field
Correct answer
the coil is parallel to the magnetic field
When the armature and field of a DC motor are supplied with current, what does the armature experience?
An unstable force that tries to halt rotation
No force at all
A force that resists rotation
A force that tries to rotate it in an appropriate direction
Correct answer
An unstable force that tries to halt rotation
A hydroelectric power plant has the following parameters:
Flow rate (Q) = 50 m³/s
Electrical power output (Pout) = 8 MW
Water density (ρ) = 1000 kg/m3
Acceleration due to gravity (g) = 10 m/s2
To achieve an overall efficiency of 80%, what should be the required net head (H)?
19.50 m
22.15 m
18.75 m
20 m
Correct answer
19.50 m
A transmission line has a span length of 300 metres, and the conductor weight is 1 .2 N/m. If the tension in the conductor is 6000 N, what is the sag?
6 m
2.25 m
5 m
1 m
Correct answer
6 m
Assertion (A): Switched Reluctance Motors (SRMs) exhibit high torque ripple. Reason (R): SRMs operate based on constant and steady excitation of stator phases.
Which of the following is correct?
A is true, but R is false.
Both A and R are true, but R is not the correct explanation of A.
A is false, but R is true.
Both A and R are true, and R is the correct explanation of A.
Correct answer
A is true, but R is false.
Which of the following statements regarding phase sequence is INCORRECT?
An incorrect phase sequence can cause a motor to run in reverse.
Phase sequence can be changed by interchanging two phases.
If two phases are interchanged, the phase sequence remains the same
The phase sequence in a three-phase system determines the direction of motor rotation.
Correct answer
An incorrect phase sequence can cause a motor to run in reverse.
At the point of saturation in a DC series motor, the torque becomes proportional to:
armature current only
both armature current and field flux
field flux only
the square of the armature current
Correct answer
armature current only
What is the primary cause of the built-in potential at a p-n junction?
Diffusion of electrons from n-type to p-type material, resulting in a potential barrier
Drift of holes from p-type to n-type material, resulting in a potential barrier
Difference in bandgap energy between p-type and n-type materials
Difference in electron affinity between p-type and n-type materials
Correct answer
Diffusion of electrons from n-type to p-type material, resulting in a potential barrier
In a three-phase system, the active power (P) is given by which of the following formulas?
√3 VLIL cos Φ
VLIL
3 VLIL cos Φ
VLIL cos Φ
Correct answer
√3 VLIL cos Φ
The important property of magnetic lines of force is that:
magnetic lines of force intersect each other at infinity
magnetic lines of force never flows in closed loop.
magnetic lines of force intersect within the magnet
no two magnetic lines of force intersect each other
Correct answer
magnetic lines of force intersect each other at infinity
What happens to the Fermi level in a p-n junction at equilibrium?
It rises in the p-side and falls in the n-side.
It remains constant throughout the junction
It disappears at the junction.
It falls in the p-side and rises in the n-side.
Correct answer
It rises in the p-side and falls in the n-side.
Two capacitors A and B are connected in series across a 200 V DC supply. The PD across A is 60 V. This PD is increased to 80 V when a 3 μF capacitor is connected in parallel with B. Calculate the capacitance of B.
7.8 µF
3.5 µF
5.4 µF
2.7 µF
Correct answer
7.8 µF
What is a key consideration when designing an electrical installation scheme for a factory?
Providing adequate protection against overloads, short circuits, and earth faults
Minimising the use of protective devices to reduce costs
Focusing only on lighting and ventilation systems
Ensuring the system is aesthetically pleasing
Correct answer
Providing adequate protection against overloads, short circuits, and earth faults
Core losses in a transformer are proportional to:
the square of the frequency
the square of the stator current
the square of the voltage
the square of the load current
Correct answer
the square of the frequency
Whenever a P-N junction diode is forward biased, the width of the space charge region _________ and the forward current __________ for rise in supply voltage.
becomes zero; increases
becomes zero; decreases
decreases; increases
increases; decreases
Correct answer
becomes zero; increases
What is the significance of the ideality factor (η) in the Shockley diode equation?
It accounts for the reverse saturation current.
It accounts for the non-ideal behaviour of the diode.
It accounts for the thermal energy of the electrons.
It accounts for the recombination of electrons and holes in the depletion region.
Correct answer
It accounts for the reverse saturation current.
What is the significance of the Quiescent point (Q-point) in a transistor amplifier circuit?
It is the point where the transistor is cut off.
It represents the minimum current gain of the transistor.
It represents the maximum power output of the amplifier.
It is the operating point where the transistor operates without an input signal.
Correct answer
It is the point where the transistor is cut off.
If the reactive power of a three-phase system is 12 kVAR and the active power is 16 kW, then what is the apparent power?
20 kVA
28 kVA
4 kVA
10 kVA
Correct answer
20 kVA
In a three-phase balanced system, if the phase voltage is represented as VA = 230 <0°, then the voltage for phase B will be _____.
VB = 230∠90°
VB = 230∠120°
VB = 230∠-120°
VB = 230∠100°
Correct answer
VB = 230∠90°
In a DC series motor, at low or light load, why is the torque low?
Due to the low armature current and low field flux
Due to the saturation of the field cores
Due to the high field flux
Due to the high armature current
Correct answer
Due to the low armature current and low field flux
Which of the following statements are correct for repulsion-induction motors?
I. They combine features of repulsion and induction motors.
II. The rotor has both commutator and squirrel-cage windings.
III. Speed decreases sharply with increasing load.
IV. They are used in applications requiring constant speed.
Statement III and IV only correct
Statement I and IV only correct
Statement I and II only correct
Statement II and III only correct
Correct answer
Statement III and IV only correct
If the capacitance C in a parallel RLC circuit decreases, what happens to resonant frequency f0?
Decreases
Increases
Remains constant
Becomes zero
Correct answer
Decreases
If wind speed doubles, the Wind Power Density increases by a factor of ________.
6
8
4
2
Correct answer
6
In a parallel resistance (R) and capacitor (C) circuit, if resistance R increases, the phase angle ϕ __________.
increases
becomes zero
remains the same
decreases
Correct answer
increases
The parameters which can be obtained from output characteristics curves of common emitter BJT NPN transistor is/are:
forward current amplification factor and input resistance of CE configuration
input resistance of CE configuration only
output resistance of CE configuration only
forward current amplification factor and output resistance of CE configuration
Correct answer
forward current amplification factor and input resistance of CE configuration
Which of the following statements is NOT correct regarding resonance in a series circuit?
The voltage across the capacitor and inductor is equal and opposite
The circuit behaves as a purely resistive circuit.
The net reactance of the circuit is zero
The phase angle of the circuit is 90°
Correct answer
The voltage across the capacitor and inductor is equal and opposite
In an SF6 (Sulphur Hexafluoride) circuit breaker, the fixed contact is:
a spherical contact with an insulating shield
a solid cylindrical contact with no additional fittings
a flat plate contact with thermal insulation
a hollow cylinder contact with an arc horn
Correct answer
a spherical contact with an insulating shield
Why are wind turbine blades made of glass fibre reinforced polyester?
To reduce cost
To provide lightweight strength and durability
To increase the efficiency of power transmission
To make them heavier for stability
Correct answer
To reduce cost
In a balanced beam type relay, what happens under normal working conditions?
The current through the coil causes the beam to tilt downward.
The beam oscillates between horizontal and tilted positions.
The spring compresses completely to maintain stability.
The beam is held in a horizontal position by the spring.
Correct answer
The current through the coil causes the beam to tilt downward.
Assertion (A): Detent torque is present in permanent magnet stepper motors even when unpowered.
Reason (R): Detent torque arises from the interaction between the rotor magnets and stator teeth.
Which of the following option is correct?
Both A and R are true, but R does not explain A.
Both A and R are false.
A is false, but R is true.
Both A and R are true, and R explains A.
Correct answer
Both A and R are true, but R does not explain A.
What happens to the depletion layer in a P-N junction when it is reverse-biased?
The depletion layer disappears.
The depletion layer narrows.
The depletion layer remains unchanged.
The depletion layer widens.
Correct answer
The depletion layer disappears.
Which of the following options is always true about the demand factor?
It is always greater than 1.
It is always equal to the utilisation factor.
It is always less than or equal to 1.
It is always equal to the diversity factor.
Correct answer
It is always greater than 1.
Laplace transform is applicable to ___________ signals.
integral time
continuous time domain
non linear
digital
Correct answer
integral time
Determine the peak value of the output signal of the half wave rectifier or a series clipper realised using a single diode having forward voltage of 0.6 V, if the input applied the circuit is periodic sinusoidal signal of 10 V peak to peak voltage.
5 V
9.4 V
10 V
4.4 V
Correct answer
5 V
In which situation will an EMF be induced in a conductor, according to Faraday's Laws?
When the temperature of the conductor increases
When the conductor is stationary in a magnetic field
When the magnetic field is constant
When there is relative motion between a conductor and a magnetic field
Correct answer
When the temperature of the conductor increases
A power plant has a rated capacity of 200 MW and operates for 10 hours per day throughout the year, generating 365,000 MWh. What is the Plant Use Factor?
85%
50%
70%
90%
Correct answer
85%
A diode rectifier circuit has an AC input voltage of 230 Vrms and a load resistance of 1 kΩ with a capacitor. The primary function of the capacitor is to:
increase the output voltage
decrease the output voltage
filter out the AC ripples and smooth the output voltage
regulate the output voltage
Correct answer
increase the output voltage
The phasor representation of current and voltage in a pure inductive circuit shows that _______.
voltage leads current by 90°
current and voltage are in phase
voltage leads current by 180°
current leads voltage by 90°
Correct answer
voltage leads current by 90°
Select the option that is correct regarding the following two statements labelled Assertion (A) and Reason (R).
Assertion (A): The neutral wire in a star-connected balanced three-phase system carries no current.
Reason (R): In a balanced system, the sum of the three-phase current phasors is always zero.
A is true, but R is false.
A is false, but R is true
Both A and R are true, but R is not the correct explanation of A
Both A and R are true, and R is the correct explanation of A.
Correct answer
A is true, but R is false.
In an induction type directional overcurrent relay, what is the net torque at the balance point when the relay is on the verge of operating?
Equal to K2
Equal to VI cos (ɵ - α)
Equal to the pick-up torque of the relay
Equal to zero
Correct answer
Equal to K2
What is a key advantage of voltage drop in a radial power distribution system?
It increases power dissipation in the form of heat.
It ensures voltage remains constant throughout the network.
It eliminates the need for voltage regulators
It limits excessive current flow, aiding in overcurrent protection.
Correct answer
It increases power dissipation in the form of heat.
How does a ring main system improve reliability?
It reduces the number of distributors.
It allows power to be supplied from two directions.
It reduces voltage drop in the system.
It eliminates the need for a transformer.
Correct answer
It reduces the number of distributors.
What does the use of a single winding in an auto transformer result in?
Higher losses
Reduced copper consumption
Lower voltage regulation
Increased size and weight
Correct answer
Higher losses
Which of the following statements is/are true?
Statement (I): High voltage drop in residential areas can cause lights to dim or flicker.
Statement (II): Voltage drop occurs due to excessive power consumption in a household.
Only Statement (II) is true.
Neither Statement (I) nor Statement (II) is true.
Only Statement (I) is true
Both Statement (I) and Statement (II) are true.
Correct answer
Only Statement (II) is true.
Which of the following is a common application of universal motors?
Refrigerators
Vacuum cleaners
Ceiling fans
Air conditioners
Correct answer
Refrigerators
Which of the following is a significant feature of Scott connection transformers?
They provide high voltage output
They convert 1-phase power into 3-phase
They provide a 2-phase output from a 3-phase input.
They are used for stepping down voltage only.
Correct answer
They provide high voltage output
What is the primary cause of junction capacitance in a p-n diode?
Variation in minority carrier concentration with applied voltage
Thermal generation of carriers in the depletion region
Change in depletion region width with applied voltage
Variation in majority carrier concentration with applied voltage
Correct answer
Variation in minority carrier concentration with applied voltage
What is the induced EMF called in a DC motor, which opposes the flow of current in the armature conductors?
Field EMF
Back EMF
Induced voltage
Supply EMF
Correct answer
Field EMF
Torque in reluctance motors is produced primarily due to?
Permanent magnet alignment
Induction principles
Magnetic saliency
Eddy current generation
Correct answer
Permanent magnet alignment
In a Synchronous reluctance motor, flux barriers are typically filled with _____________
Ferrite
Copper
Laminated steel
Air or non-magnetic material
Correct answer
Ferrite
For a BJT, determine the emitter current if the collector current is 1 mA and the common base short circuit amplification factor is unity.
1.5 mA
2 mA
1 mA
0.5 mA
Correct answer
1.5 mA
For a Zener diode working in reverse bias condition, the Zener current is _________ for supply voltage _________ the Reverse Zener breakdown voltage.
close to zero; greater than
close to zero; less than
close to infinity; greater than
close to infinity; less than
Correct answer
close to zero; greater than
Which of the following is NOT an advantage of the underground system over the overhead system?
Reduced voltage drops
Better aesthetics and safety
Lower chances of power failures
Tapping for loads and service mains is easier
Correct answer
Reduced voltage drops
How can eddy current loss be reduced in the armature core?
By increasing the motor's speed
By increasing the core resistance
By using a high resistance core material
By laminating the core to reduce the flow of eddy currents
Correct answer
By increasing the motor's speed
What is a critical factor in the selection of cables for outdoor public lighting installations?
Ignoring voltage drop calculations to reduce costs.
The cable's ability to withstand environmental conditions and carry the required current safely
Selecting the cheapest cable available.
The colour of the cable insulation
Correct answer
Ignoring voltage drop calculations to reduce costs.
Why do inverted V-curves have an inverted "V" shape ?
Mechanical load affects excitation linearly
Power factor peaks at optimal excitation (unity PF)
Stator resistance varies non-linearly with excitation
Armature current peaks at unity power factor
Correct answer
Mechanical load affects excitation linearly
The S.I. unit of work is ______ and energy is ______.
Watt; Joule
Newton; Newton
Joule; Joule
Joule; Newton
Correct answer
Watt; Joule
The maximum fault current reached before a fuse melts is called:
rupturing current
holding current
cut-off current
peak current
Correct answer
rupturing current
Inductance of a coil ___________ when we place an iron bar inside it.
reduces to zero
increases
remains unchanged
decreases
Correct answer
reduces to zero
A hydro power plant with an installed capacity of 10 MW falls under which of the following categories?
Small hydro
Mini hydro
Medium hydro
Large hydro
Correct answer
Small hydro
One big CHALLENGE with Solar Panels (PV) compared to Concentrating Solar Power (CSP) is:
they have lots of moving parts, making maintenance costly
they need costly batteries to store power for nighttime use
they completely stop working on cloudy days
they need high-tech factories to be made
Correct answer
they have lots of moving parts, making maintenance costly
A current impulse signal of 4 δ(t) is forced through a capacitor C. The voltage Vc (t) across capacitor is given by:
\(\rm \frac{4}{C}t\)
\(\rm \frac{4.u(t)}{C}\)
4.u(t)-C
4.t
Correct answer
\(\rm \frac{4}{C}t\)
Match the following sources of error in a CT with their corresponding causes
| Error Type | Cause | ||
|---|---|---|---|
| 1. | Ratio Error | A. | Leakage flux in windings |
| 2. | Phase Angle Error | B. | Magnetising current requirement |
| 3. | Hysteresis Error | C. | Non-ideal core material properties |
| 4. | Leakage Reactance Error | D. | Residual magnetism in the core |
1 → A, 2 → B, 3 → D, 4 → C
1 → B, 2 → A, 3 → D, 4 → C
1 → B, 2 → C, 3 → D, 4 → A
1 → B, 2 → A, 3 → C, 4 → D
Correct answer
1 → A, 2 → B, 3 → D, 4 → C
Ohm's law for a magnetic circuit is given by ratio of:
magnetic reluctance to magnetic flux
magnetic reluctance to magnetomotive force
magnetomotive force to magnetic reluctance
magnetomotive force to permeance
Correct answer
magnetic reluctance to magnetic flux
What is the primary purpose of preparing a material schedule and detailed estimation for an industrial installation?
To provide a comprehensive list of materials and costs for accurate project planning and execution
To eliminate the need for protective devices in the system
To focus only on the aesthetic aspects of the installation
To ensure the project is completed without any documentation
Correct answer
To provide a comprehensive list of materials and costs for accurate project planning and execution
In a Francis turbine, which of the following components dynamically adjust(s) to regulate the flow rate and optimise power output under varying load conditions?
Guide vanes
Spiral casing
Draft tube
Runner blades
Correct answer
Guide vanes
Which of the following statements best describes the benefit of a Power Factor Tariff in energy conservation?
It increases the overall electricity cost regardless of power factor improvement
It has no impact on energy conservation or system efficiency.
It only applies to residential consumers and does not affect industrial or commercial users.
It encourages consumers to maintain a high power factor, reducing losses and improving system efficiency.
Correct answer
It increases the overall electricity cost regardless of power factor improvement
For a voltage divider bias circuit in CE configuration using NPN BJT transistor, Vcc = 10 V and the resistance at collector and emitter is Rc = 2 kΩ and RE = 500 Ω, respectively. (Assume DC current gain Beta of transistor as very high) Determine the approximate maximum value of collector current for the voltage divider bias circuit.
5 mA
4 mA
2.5 mA
20 mA
Correct answer
5 mA
Select the correct advantage of a full-wave rectifier over a half-wave rectifier
Lower efficiency and utilisation of only one half-cycle of the AC input
Lower cost
Higher efficiency and utilisation of both half-cycles of the AC input
Lower output voltage
Correct answer
Lower efficiency and utilisation of only one half-cycle of the AC input
What is a critical consideration in the design and estimation of street lighting costs?
Calculating the number of light fixtures, cable requirements, and energy consumption to determine overall costs
Focusing only on the aesthetic design of the streetlights
Ignoring energy efficiency to reduce initial costs
Eliminating the use of protective devices in the system
Correct answer
Calculating the number of light fixtures, cable requirements, and energy consumption to determine overall costs
For small capacity motors (up to 3 Hp), what voltage can be applied at startup?
Zero voltage
Double the normal voltage
Half the normal voltage
Full normal voltage
Correct answer
Zero voltage
Force acting on two parallel current-carrying conductors is __________, if the current is in the same direction.
zero
infinite
repulsive
attractive
Correct answer
zero
An alternating current is one whose magnitude ______ and direction ______.
changes continuously; changes periodically
does not change; remains the same
does not change; changes periodically
changes continuously; remain the same
Correct answer
changes continuously; changes periodically
Copper losses in a transformer are proportional to:
the square of the load current
the square of the frequency
the square of the turns ratio
the square of the voltage
Correct answer
the square of the load current
Which of the following parameters can be controlled by an AC/DC drive?
Speed, torque and horsepower
Torque, direction of AC motor and speed
Speed and torque
Speed, torque, horsepower, and direction of AC motor
Correct answer
Speed, torque and horsepower
150 questions in the full paper