MES Departmental • 2025 • Paper-II
Which of the following power semiconductor devices has the highest switching speed?
A)
BJT
B)
IGBT
C)
Power MOSFET
D)
SCR
Option C is correct: Power MOSFET.
MES Departmental • 2025 • Paper-II
In a series connection of resistors, what happens to the current across each resistor?
A)
Increases
B)
Decreases
C)
Remains the same
D)
Initially increases and then decreases
Option C is correct: Remains the same.
MES Departmental • 2025 • Paper-II
In a power triangle, what is the relationship between active power (P), reactive power (Q), and apparent power (S)?
A)
P + Q = S
B)
P² + Q² = S²
C)
P = Q + S
D)
S² + Q² = P
Option B is correct: P² + Q² = S².
MES Departmental • 2025 • Paper-II
How does earthing contribute to system stability?
A)
By introducing resistance in the neutral
B)
By providing a stable reference point (zero potential) for the system
C)
By increasing system impedance
D)
By creating an isolated neutral
Option B is correct: By providing a stable reference point (zero potential) for the system.
MES Departmental • 2025 • Paper-II
What is a common maintenance task for Power Transformers in outdoor substations?
A)
Changing the tank paint every year.
B)
Checking oil level, colour, and moisture content, plus oil testing.
C)
Removing all bushings for cleaning.
D)
Reducing the load to below 50%.
Option B is correct: Checking oil level, colour, and moisture content, plus oil testing..
MES Departmental • 2025 • Paper-II
What is the primary function of an inductor in an AC circuit?
A)
To store energy in a magnetic field
B)
To oppose a change in circuit current
C)
Both (a) and (b)
D)
To convert electrical energy to mechanical energy
Option C is correct: Both (a) and (b).
MES Departmental • 2025 • Paper-II
Which of the following activities is typically part of routine (preventive/scheduled) maintenance of HT/LT ABC lines?
A)
Replacement of worn-out parts
B)
Troubleshooting during a breakdown
C)
Regular inspection for physical damage, wear or sagging of the cable
D)
Re-varnishing of the cable
Option C is correct: Regular inspection for physical damage, wear or sagging of the cable.
MES Departmental • 2025 • Paper-II
Alternators and AC generators work on the principle of:
A)
Fleming’s left-hand rule
B)
Lenz’s Law
C)
Faraday’s law of electromagnetic induction
D)
Ohm’s Law
Option C is correct: Faraday’s law of electromagnetic induction.
MES Departmental • 2025 • Paper-II
What is the primary instrument used specifically for measuring earth resistance?
A)
Ammeter
B)
Voltmeter
C)
Earth Tester (or Ground Resistance Tester)
D)
Frequency Meter
Option C is correct: Earth Tester (or Ground Resistance Tester).
MES Departmental • 2025 • Paper-II
When is the efficiency of a transformer maximum?
A)
At no load
B)
When copper loss equals iron loss
C)
At half load
D)
When voltage is maximum
Option B is correct: When copper loss equals iron loss.
MES Departmental • 2025 • Paper-II
The primary consideration for a transmission substation site is:
A)
Proximity to residential areas
B)
High population density
C)
Proximity to load centers & transmission line corridors
D)
Close to airports
Option C is correct: Proximity to load centers & transmission line corridors.
MES Departmental • 2025 • Paper-II
The common type of storage battery generally used in electric power stations is the:
A)
Nickel-cadmium battery
B)
Zinc-carbon battery
C)
Lead-acid battery
D)
Lithium-ion battery
Option C is correct: Lead-acid battery.
MES Departmental • 2025 • Paper-II
Which power is the actual power that performs useful work in a circuit?
A)
Reactive Power
B)
Active Power
C)
Apparent Power
D)
Absolute Power
Option B is correct: Active Power.
MES Departmental • 2025 • Paper-II
Lenz’s law is related to:
A)
the direction of magnetic field
B)
the direction of motion of conductor
C)
the direction of the induced current
D)
Both (a) and (b)
Option C is correct: the direction of the induced current.
MES Departmental • 2025 • Paper-II
The function of a protective relay is to:
A)
Detect the fault and initiate the operation of the circuit breaker
B)
Absorb the fault current
C)
Step down the voltage for metering
D)
Provide an alarm only during a fault
Option A is correct: Detect the fault and initiate the operation of the circuit breaker.
MES Departmental • 2025 • Paper-II
A major constraint for substation location is proximity to:
A)
River crossings
B)
Industrial zones
C)
Airports & defense establishments
D)
Agricultural lands
Option C is correct: Airports & defense establishments.
MES Departmental • 2025 • Paper-II
In a balanced delta-connected system, the line voltage (VL) is
A)
VL = 0.707 × Vph
B)
VL = 1.732 × Vph
C)
VL = 1.414 × Vph
D)
VL = Vph
Option D is correct: VL = Vph.
MES Departmental • 2025 • Paper-II
Which of the following is a method to reduce skin effect losses in a transmission line?
A)
Using solid conductors
B)
Increasing the frequency
C)
Using stranded conductors
D)
Increasing conductor resistance
Option C is correct: Using stranded conductors.
MES Departmental • 2025 • Engineering Paper-II
In how many groups, various metal working processes can be classified?
A)
2
B)
3
C)
4
D)
none of the mentioned
Option C is correct: 4.
MES Departmental • 2025 • Engineering Paper-II
What is the purpose of a circuit diagram?
A)
To represent the physical layout of a circuit
B)
To represent the electrical connections and components of a circuit
C)
To show the location of the components in a building
D)
To show the physical size of the components
Option B is correct: To represent the electrical connections and components of a circuit.
MES Departmental • 2025 • Engineering Paper-II
Which of the following lighting schemes is least suitable for a high-traffic public space, like a shopping mall?
A)
Direct lighting
B)
Semi-direct lighting
C)
Indirect lighting
D)
A combination of direct and indirect lighting
Option C is correct: Indirect lighting.
MES Departmental • 2025 • Engineering Paper-II
Which of the following is the common application of Air standard refrigeration system?
A)
Cold storage
B)
Car air conditioning system
C)
Domestic refrigerators
D)
Aircraft air conditioning
Option D is correct: Aircraft air conditioning.
MES Departmental • 2025 • Engineering Paper-II
What is a circuit diagram also known as?
A)
A blueprint
B)
An elementary diagram
C)
A blueprint of a building
D)
A schematic diagram
Option D is correct: A schematic diagram.
MES Departmental • 2025 • Engineering Paper-II
Which of the following process is used in winter air conditioning?
A)
Cooling and Dehumidification
B)
Heating and Humidification
C)
Dehumidification
D)
Humidification
Option B is correct: Heating and Humidification.
MES Departmental • 2025 • Engineering Paper-II
What is the purpose of using a diffuser in a lighting fixture?
A)
To increase the luminous flux
B)
To improve the color rendering index (CRI)
C)
To reduce glare and reflections
D)
To increase the energy efficiency of the fixture
Option C is correct: To reduce glare and reflections.
