MES Departmental • 2025 • Engineering Paper-II
What is the main goal of preventive maintenance in an outdoor substation?
A)
To fix faults immediately after they occur.
B)
To identify and rectify potential issues before they cause failure, ensuring reliability.
C)
To repaint everything every few years.
D)
To replace all equipment every decade
Option B is correct: To identify and rectify potential issues before they cause failure, ensuring reliability..
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
Which of the following is an advantage of multi-stage air compression?
A)
Increased leakage loss
B)
Reduced work input
C)
Lower volumetric efficiency
D)
Increased discharge temperature
Option B is correct: Reduced work input.
MES Departmental • 2025 • Engineering Paper-II
Which of the following is a necessary component for a centrifugal pump to be able to self-prime?
A)
A draft tube
B)
A separate priming chamber or internal suction stage
C)
A larger impeller
D)
A high-speed motor
Option B is correct: A separate priming chamber or internal suction stage.
MES Departmental • 2025 • Engineering Paper-II
Which protection scheme is generally recommended for Power transformers with a rating above 5MVA?
A)
Over-current protection
B)
Differential protection
C)
Restricted Earth Fault protection
D)
Buchholz relay
Option B is correct: Differential protection.
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
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
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
In a Francis turbine, what does the governor control to regulate the water flow?
A)
The spear nozzle
B)
The draft tube
C)
The wicket gates
D)
The runner blades
Option C is correct: The wicket gates.
MES Departmental • 2025 • Engineering 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 • 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
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 • 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
How are turbines classified based on the energy available at the inlet?
A)
Tangential, radial, and axial flow
B)
High head, medium head, and low head
C)
Impulse and reaction turbines
D)
Mixed flow and tangential flow
Option C is correct: Impulse and reaction turbines.
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
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
What is the hydraulic efficiency of a turbine?
A)
The ratio of power delivered to the runner to the power supplied at the inlet
B)
The ratio of power at the shaft to the power delivered to the runner
C)
The ratio of shaft power to the total power supplied by the water
D)
The ratio of power generated to the water power input
Option A is correct: The ratio of power delivered to the runner to the power supplied at the inlet.
MES Departmental • 2025 • Engineering Paper-II
Gas turbines are best suited for which type of power plant application?
A)
Base load power plants
B)
Peak load power plants
C)
Geothermal power plants
D)
Nuclear power plants
Option B is correct: Peak load power plants.
MES Departmental • 2025 • Engineering Paper-II
What is the primary purpose of switchgear in an electrical power system?
A)
To generate electricity
B)
To step up or step down voltage levels
C)
To protect, control, and isolate electrical equipment
D)
To measure power consumption
Option C is correct: To protect, control, and isolate electrical equipment.
MES Departmental • 2025 • Engineering Paper-II
The primary purpose of performance testing a turbine is to determine its:
A)
Specific speed
B)
Maximum power output and efficiency
C)
Physical dimensions
D)
Operating noise level
Option B is correct: Maximum power output and efficiency.
MES Departmental • 2025 • Engineering Paper-II
In case of an insulation failure, earthing provides:
A)
A high-resistance path
B)
The easiest path for short-circuit current to flow to the ground
C)
A path to the live wire
D)
An open circuit
Option B is correct: The easiest path for short-circuit current to flow to the ground.
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
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.
