O&m Engineer - Electrical Interview Questions and Answers in 2025 (100+ Q&A)

Ques:- What is HT cable?

Right Answer:
HT cable, or High Tension cable, is used to transmit electrical power at high voltages, typically above 1 kV, for efficient long-distance power distribution.

Electrical O&m Engineer - Electrical

Ques:- Regarding earthing, pf, why transformers are rated in KVA,

Asked In :- Franke Faber India, forbes marshall,

Right Answer:
Transformers are rated in KVA because their capacity is based on the apparent power (voltage and current) they can handle, regardless of the power factor. This allows for a consistent rating that applies to various loads with different power factors.

Electrical O&m Engineer - Electrical

Ques:- How you control stepper motor.

Asked In :-

Right Answer:
To control a stepper motor, you can use a microcontroller to send pulses to the motor driver. Each pulse moves the motor one step. You can control the speed by adjusting the frequency of the pulses and the direction by changing the sequence of the pulses sent to the motor coils.

Electrical O&m Engineer - Electrical

Ques:- Tell us about switch yard and transmission line.

Asked In :- Worley Parsons,

Right Answer:
A switchyard is a part of an electrical power system where the transmission lines connect to transformers and other equipment. It facilitates the switching, controlling, and protection of electrical power. Transmission lines are high-voltage cables that carry electricity over long distances from power plants to substations, minimizing energy loss. Together, they ensure efficient and reliable delivery of electricity to consumers.

Electrical O&m Engineer - Electrical

Ques:- What is difference between DC and Ac

Asked In :- Urenco, Somic ZF Components, ethiopian electric power corp.,

Right Answer:
DC (Direct Current) flows in one direction and has a constant voltage, while AC (Alternating Current) changes direction periodically and has a varying voltage.

O&m Engineer - Electrical Personal Questions round

Ques:- What if you get a canada degree in india ,would you like to go to canada again for higher studies?

Asked In :- Capacite Infraprojects, Mahagenco, sidel,

Right Answer:
Yes, I would consider going to Canada for higher studies, as it offers diverse opportunities and a different academic environment.

Electrical O&m Engineer - Electrical

Ques:- Why vacuume circuit breaker is not used for EHV

Asked In :- Fluor Daniel, lam research, liberty utilities,

Right Answer:
Vacuum circuit breakers are not used for Extra High Voltage (EHV) applications primarily due to their limited interrupting capacity and the challenges in maintaining a vacuum seal at higher voltages, which can lead to reliability issues. Additionally, EHV systems require more robust insulation and switching technologies that are better suited to air-insulated or gas-insulated switchgear.

Electrical O&m Engineer - Electrical

Ques:- How to measure ducting in HVAC.

Asked In :-

Right Answer:
To measure ducting in HVAC, use the following steps:

1. **Measure Length**: Use a tape measure to determine the straight length of each duct run.
2. **Measure Width and Height**: For rectangular ducts, measure the width and height. For round ducts, measure the diameter.
3. **Calculate Area**: For rectangular ducts, multiply width by height. For round ducts, use the formula π × (diameter/2)² to find the cross-sectional area.
4. **Total Duct Area**: Sum the areas of all duct sections to get the total duct area.
5. **Account for Fittings**: Measure and include any fittings (elbows, transitions) as they can affect airflow and sizing.

Ensure all measurements are in the same units for consistency.

Electrical O&m Engineer - Electrical

Ques:- WHAT IS TRANSVERSE WEIGHT SHIFT DUE TO DRIVE TORQUE?

Asked In :- Energytech Global, Somic ZF Components, powerlink queensland,

Right Answer:
Transverse weight shift due to drive torque refers to the lateral shift in weight distribution of a vehicle or system when torque is applied to the drive wheels, causing a change in the center of gravity and potentially affecting stability and handling.

Electrical O&m Engineer - Electrical

Ques:- Give the expression for CMOS switching power dissipation?

Asked In :- L&T Valves, cipet,

Right Answer:
The expression for CMOS switching power dissipation is given by:

[ P_{dynamic} = frac{1}{2} C_{load} V_{DD}^2 f ]

where ( P_{dynamic} ) is the dynamic power dissipation, ( C_{load} ) is the load capacitance, ( V_{DD} ) is the supply voltage, and ( f ) is the switching frequency.

O&m Engineer - Electrical Personal Questions round

Ques:- What elements of your job do you find most difficult?

Asked In :- roto,

Right Answer:
The most difficult elements of my job include troubleshooting complex electrical issues under time pressure and ensuring compliance with safety regulations while managing multiple tasks.

Electrical O&m Engineer - Electrical

Ques:- What is the Full form of Rccb,MCCB,

Asked In :- Delta India Electronics, etas, torc robotics,

Right Answer:
RCCB: Residual Current Circuit Breaker
MCCB: Molded Case Circuit Breaker

Electrical O&m Engineer - Electrical

Ques:- What is the formula for converting KW into KWH ?

Asked In :- brakes india limited,

Right Answer:
KWH = KW × Hours.

Electrical O&m Engineer - Electrical

Ques:- Which has more losses, AC or DC??

Asked In :- smith & nephew,

Right Answer:
AC has more losses than DC due to factors like skin effect and reactive power.

Electrical O&m Engineer - Electrical

Ques:- What is protection class current transformer.

Asked In :- Harrier Information Systems, ariosh,

Right Answer:
A protection class current transformer is designed to provide accurate current measurements for protective relaying and circuit protection. It has a high accuracy at rated current and is built to withstand fault conditions, ensuring reliable operation during short circuits or overloads.

Electrical O&m Engineer - Electrical

Ques:- What is PIR (pre inserting resistance) in 400kv EHV SF6 BREAKER? Why it use?

Asked In :-

Right Answer:
PIR (Pre-Inserting Resistance) in a 400kV EHV SF6 breaker is a resistance that is temporarily connected in series with the circuit during the closing operation of the breaker. It is used to limit the inrush current and to ensure a smooth and controlled closing of the breaker, preventing damage to the equipment and ensuring reliable operation.

O&m Engineer - Electrical Personal Questions round

Ques:- What you have learn from your MBA?

Asked In :-

Right Answer:
I learned valuable skills in leadership, strategic thinking, financial analysis, and effective communication, which are essential for managing teams and projects in the engineering field.

Electrical O&m Engineer - Electrical

Ques:- How instantanious short circuit current is calculated ? its formula.

Asked In :-

Right Answer:
The instantaneous short circuit current (Isc) can be calculated using the formula:

[ I_{sc} = frac{V_{ph}}{Z_{total}} ]

Where:
- ( I_{sc} ) = Instantaneous short circuit current
- ( V_{ph} ) = Phase voltage at the point of fault
- ( Z_{total} ) = Total impedance (including the source and the fault path) at the point of fault.

Electrical O&m Engineer - Electrical

Ques:- In brushless excitation system how generator field current is measure even if the slip rings are absent?

Asked In :- guardant health,

Right Answer:
In a brushless excitation system, the generator field current is measured using a rotor-mounted sensor, such as a Hall effect sensor or a current transformer, which detects the magnetic field produced by the rotor's winding, allowing for accurate measurement without the need for slip rings.

Electrical O&m Engineer - Electrical

Ques:- Why current leads the voltage in case of capacitor load?Why voltage leads the current in case of inductive load?Why both are with in phase in case of restive load?

Asked In :- Skoda,

Right Answer:
In a capacitor load, current leads voltage because the capacitor charges and discharges before the voltage reaches its peak. In an inductive load, voltage leads current because the inductor resists changes in current, causing the voltage to reach its peak first. In a resistive load, current and voltage are in phase because they rise and fall together without any delay.

The O&M Engineer – Electrical category on takluu.com is specially curated for electrical engineers aiming to excel in operation and maintenance roles. Operation and Maintenance (O&M) engineers play a crucial role in ensuring the efficient functioning, reliability, and safety of electrical systems in industrial and commercial setups.

This section covers essential topics such as electrical equipment maintenance, preventive and predictive maintenance techniques, fault diagnosis, electrical safety standards, and system optimization. You will also find questions on power distribution, switchgear, transformers, motors, and troubleshooting electrical faults.

Interviewers commonly focus on practical knowledge and problem-solving skills, asking questions like:

“How do you perform preventive maintenance on transformers?”
“Explain the steps to troubleshoot an electrical motor failure.”
“What safety measures are essential during electrical equipment maintenance?”

Our content explains complex electrical O&M concepts in an easy-to-understand manner, supported by real-world examples and best practices. Whether you are a fresher or an experienced engineer, this category will help you build confidence and prepare thoroughly for technical interviews.

At Takluu, we regularly update the O&M Engineer – Electrical category with the latest industry standards, technologies, and safety regulations, ensuring you stay current and competitive.

Questions in: O&m Engineer - Electrical

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