Departmental (other) • 2026 • Paper-II
What is the primary purpose of measuring soil resistivity?
A)
To test cable insulation
B)
To design an effective and safe earthing/grounding system
C)
To measure fault currents
D)
To check transformer efficiency
Option B is correct: To design an effective and safe earthing/grounding system.
Departmental (other) • 2026 • Paper-II
Superposition theorem can be applied only to circuits having:
A)
resistive elements
B)
passive elements
C)
non-linear elements
D)
linear bilateral elements
Option D is correct: linear bilateral elements.
Departmental (other) • 2026 • Paper-II
What is the property of magnetic materials?
A)
resistivity
B)
conductivity
C)
permeability
D)
ductility
Option C is correct: permeability.
Departmental (other) • 2026 • Paper-II
Which of the following is the most advanced, programmable relay that combines multiple protection, measurement, and monitoring functions in a single unit?
A)
Static Relay
B)
Electromechanical Relay
C)
Numerical Relay
D)
Reed Relay
Option C is correct: Numerical Relay.
Departmental (other) • 2026 • Paper-II
Which of the following is used to reduce the earth’s resistivity?
A)
Using copper instead of GI pipe
B)
Increasing the depth of the earth electrode
C)
Adding salt and charcoal layers in the earth pit
D)
Increasing the length of the earth wire
Option C is correct: Adding salt and charcoal layers in the earth pit.
Departmental (other) • 2026 • Paper-II
Which of the following circuit breakers requires virtually no maintenance?
A)
Air blast circuit breaker
B)
Minimum oil circuit breaker
C)
Vacuum circuit breaker
D)
SF6 circuit breaker
Option C is correct: Vacuum circuit breaker.
Departmental (other) • 2026 • Paper-II
A perfect conductor has:
A)
zero conductivity
B)
unity conductivity
C)
infinite conductivity
D)
none of the above
Option C is correct: infinite conductivity.
Departmental (other) • 2026 • Paper-II
In electrical instruments, what is typically the most efficient form of damping?
A)
Air damping
B)
Fluid friction
C)
Eddy currents
D)
Magnetic friction
Option C is correct: Eddy currents.
Departmental (other) • 2026 • Paper-II
What is the fundamental working principle of a Differential Relay used for transformer protection?
A)
It measures the impedance (Z) to the fault.
B)
It detects gas accumulation in oil-filled tanks.
C)
It compares the currents entering and leaving the protected zone.
D)
It trips when the voltage exceeds safe limits.
Option C is correct: It compares the currents entering and leaving the protected zone..
Departmental (other) • 2026 • Paper-II
Which devices are connected directly to the secondary of a Current Transformer?
A)
Voltmeters and potential coils of wattmeters
B)
Ammeters and current coils of wattmeters
C)
Frequency meters
D)
Power factor indicators
Option B is correct: Ammeters and current coils of wattmeters.
Departmental (other) • 2026 • Paper-II
What is the primary purpose of earthing?
A)
To increase the resistance of the circuit
B)
To prevent electric shock by providing a low-resistance path for faulty current
C)
To increase the power factor of the system
D)
To protect against over-currents only
Option B is correct: To prevent electric shock by providing a low-resistance path for faulty current.
Departmental (other) • 2026 • Paper-II
How is a Potential Transformer (PT) connected in a power system?
A)
In series with the load
B)
In parallel with the line being measured
C)
In series-parallel
D)
Across the neutral only
Option B is correct: In parallel with the line being measured.
Departmental (other) • 2026 • Paper-II
What is the approximate specific gravity of the electrolyte in a fully charged lead-acid battery?
A)
1.1
B)
1.20
C)
1.29
D)
1.5
Option C is correct: 1.29.
Departmental (other) • 2026 • Paper-II
What is the primary function of indoor Control & Relay (C&R) panels in a substation?
A)
To step down transmission voltage to distribution voltage
B)
To house protection relays, control switches, and measuring instruments for supervising outdoor equipment
C)
To mechanically isolate the high voltage lines
D)
To cool down power transformers
Option B is correct: To house protection relays, control switches, and measuring instruments for supervising outdoor equipment.
Departmental (other) • 2026 • Paper-II
What is the standard SI unit for measuring soil resistivity?
A)
Ohm-centimeter
B)
Ohm-meter (V.m)
C)
Siemens/meter
D)
Ohms (V)
Option B is correct: Ohm-meter (V.m).
Departmental (other) • 2026 • Paper-II
Which of the following quantities consists of the SI unit “Hertz”?
A)
Charge
B)
Force
C)
Frequency
D)
Power
Option C is correct: Frequency.
Departmental (other) • 2026 • Paper-II
The earth electrode provides:
A)
Low resistance
B)
High resistance
C)
Medium resistance
D)
Very high resistance
Option A is correct: Low resistance.
Departmental (other) • 2026 • Paper-II
Which relay is primarily used to protect transformers against external short-circuits and persistent overloads?
A)
Differential relay
B)
Buchholz relay
C)
Overcurrent relay
D)
Restricted Earth Fault (REF) relay
Option C is correct: Overcurrent relay.
Departmental (other) • 2026 • Paper-II
Which of the following devices is used to measure power in AC circuits?
A)
Ammeter
B)
Voltmeter
C)
Ohmmeter
D)
Wattmeter
Option D is correct: Wattmeter.
Departmental (other) • 2026 • Paper-II
In a three phase circuit, true power:
A)
cannot exceed apparent power
B)
can exceed apparent power
C)
is equal to apparent power
D)
always exceeds apparent power
Option A is correct: cannot exceed apparent power.
Departmental (other) • 2026 • Paper-II
Why is the secondary of a current transformer (CT) always shorted under operating conditions?
A)
Protect the windings
B)
Avoid core saturation and high voltage induction
C)
Keep it safe for human beings
D)
Protect the primary circuit
Option B is correct: Avoid core saturation and high voltage induction.
Departmental (other) • 2026 • Paper-II
Which of the following is the SI unit for electric current?
A)
Volt
B)
Ohm
C)
Ampere
D)
Watt
Option C is correct: Ampere.
Departmental (other) • 2026 • Paper-II
Which of the following areas should be strictly avoided when selecting a substation site?
A)
Flat terrain
B)
Areas near existing transmission lines
C)
Airports and defense establishments
D)
Agricultural land
Option C is correct: Airports and defense establishments.
Departmental (other) • 2026 • Paper-II
The supply voltage of a consumer is 220VAC and his internal wiring is protected by 9A fuse. How many 60W bulb in parallel can be turned on simultaneously without breaking the fuse?
A)
33 nos
B)
44 nos
C)
22 nos
D)
20 nos
Option A is correct: 33 nos.
Departmental (other) • 2026 • Paper-II
In a distribution system, what type of transformer connection is typically used to step down the voltage at the load side?
A)
Delta-Delta
B)
Star-Star
C)
Delta-Star
D)
Star-Delta
Option C is correct: Delta-Star.
