MES Departmental • 2025 • Engineering Paper-II
What is magnetizing inrush current?
A)
Current during heavy load
B)
Current during fault
C)
A transient rush of current (6 to 8 times rated current) when first energized
D)
Current during unloading
Option C is correct: A transient rush of current (6 to 8 times rated current) when first energized.
MES Departmental • 2025 • Engineering Paper-II
Where should lightning arresters be installed for optimal transformer protection?
A)
Inside the transformer tank
B)
At the termination point of overhead lines leading to the transformer
C)
On the ground below the transformer
D)
Only on the low-voltage side
Option B is correct: At the termination point of overhead lines leading to the transformer.
MES Departmental • 2025 • Engineering Paper-II
A vertical turbine pump is primarily used to move water from what sources?
A)
Shallow ponds
B)
Above-ground storage tanks
C)
Underground wells or reservoirs
D)
Pressurized pipelines
Option C is correct: Underground wells or reservoirs.
MES Departmental • 2025 • Engineering Paper-II
If a section of LT ABC is experiencing frequent faults due to illegal tapping (hooking), which inherent feature of ABC helps mitigate this issue?
A)
The use of a messenger wire
B)
The insulated nature of all conductors
C)
Its high mechanical strength
D)
Its ability to be run concurrently with communication lines
Option B is correct: The insulated nature of all conductors.
MES Departmental • 2025 • Engineering Paper-II
Which of the following is a major application of gas welding, particularly for repair work?
A)
Shipbuilding
B)
Piping systems
C)
Repairing sheet metal
D)
Structural steel fabrication
Option C is correct: Repairing sheet metal.
MES Departmental • 2025 • Engineering Paper-II
What is the primary purpose of laminating a transformer core?
A)
To increase flux density
B)
To reduce eddy current losses.
C)
To improve insulation
D)
To increase mechanical strength
Option B is correct: To reduce eddy current losses..
MES Departmental • 2025 • Engineering 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 • Engineering Paper-II
Where is cavitation most likely to occur in a hydraulic turbine?
A)
At the inlet of the penstock.
B)
On the surface of the runner vanes.
C)
At the inlet of the draft tube.
D)
On the casing of the turbine.
Option C is correct: At the inlet of the draft tube..
MES Departmental • 2025 • Engineering Paper-II
What is the purpose of a hoisting chain?
A)
To transfer power between sprockets
B)
To lift heavy loads and materials
C)
To transmit motion in a machine
D)
To measure distances on a field
Option B is correct: To lift heavy loads and materials.
MES Departmental • 2025 • Engineering 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 • Engineering Paper-II
What does a high specific speed for a turbine imply?
A)
The turbine will have a larger size for the same power output compared to an impulse turbine.
B)
The turbine is better suited for high-head, low-flow applications.
C)
The turbine is likely an impulse turbine.
D)
The turbine will be smaller in size and will generate more power for the same head
Option D is correct: The turbine will be smaller in size and will generate more power for the same head.
MES Departmental • 2025 • Engineering Paper-II
Testing of a newly installed turbine is often performed to ensure it meets the manufacturer’s guaranteed performance and efficiency under specific operating conditions, also known as
A)
Commissioning tests
B)
Maintenance tests
C)
Research tests
D)
Reliability tests
Option A is correct: Commissioning tests.
MES Departmental • 2025 • Engineering Paper-II
Before starting the electric motor of a centrifugal pump, which action is mandatory?
A)
Ensuring the delivery valve is open
B)
Checking that the pump is properly primed
C)
Adjusting the speed of the motor to maximum
D)
Closing the suction valve
Option B is correct: Checking that the pump is properly primed.
MES Departmental • 2025 • Engineering 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 • Engineering 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 • Engineering 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 • Engineering Paper-II
Which relay protects the transformer from external short circuits and overloads?
A)
Differential Relay
B)
Buchholz Relay
C)
Overcurrent Relay
D)
Thermal Relay
Option C is correct: Overcurrent Relay.
MES Departmental • 2025 • Engineering 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 • Engineering Paper-II
For having the highest fin effectiveness for heat transfer, the fins should be:
A)
Long and thin
B)
Short and thick
C)
Short and thin
D)
Long and thick
Option A is correct: Long and thin.
MES Departmental • 2025 • Engineering Paper-II
Which of the following processes is used in winter air conditioning to provide comfort?
A)
Cooling and dehumidification
B)
Heating and humidification
C)
Dehumidification only
D)
Humidification only
Option B is correct: Heating and humidification.
MES Departmental • 2025 • Engineering Paper-II
Which type of gear is used to transmit power between two shafts that are parallel to each other?
A)
Bevel gear
B)
Worm gear
C)
Spur gear
D)
Spiral bevel gear
Option C is correct: Spur gear.
MES Departmental • 2025 • Engineering Paper-II
For a head of 10-70 meters, which turbine is the most suitable choice?
A)
Pelton Turbine
B)
Kaplan Turbine
C)
Francis Turbine
D)
None of the above
Option C is correct: Francis Turbine.
MES Departmental • 2025 • Engineering Paper-II
Why are off-load tap changers operated only when the transformer is de-energized?
A)
To prevent sparking
B)
To avoid damaging the mechanism
C)
To ensure safety and proper contact engagement
D)
They don’t require power
Option A is correct: To prevent sparking.
MES Departmental • 2025 • Engineering 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 • Engineering Paper-II
Which of the following is the most crucial fluid property to consider when selecting a centrifugal pump, as it directly impacts the required motor power?
A)
Color of the fluid
B)
Odour of the fluid
C)
Specific gravity of the fluid
D)
Boiling point of the fluid
Option C is correct: Specific gravity of the fluid.
