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

Ques:- What skills do you have?

Asked In :- relativity,

Right Answer:
I have skills in circuit design, PCB layout, embedded systems programming, power electronics, and proficiency in simulation software like MATLAB and SPICE. Additionally, I am experienced in troubleshooting and testing electrical systems.

Design Engineer - Electrical Electrical

Ques:- How to calculate knee point voltage of current transformer?

Asked In :- Pinaka Aerospace Solutions,

Right Answer:
The knee point voltage of a current transformer (CT) can be calculated using the formula:

[ V_k = frac{I_s times R}{sqrt{3}} ]

where ( V_k ) is the knee point voltage, ( I_s ) is the saturation current of the CT, and ( R ) is the burden resistance connected to the CT.

Design Engineer - Electrical Electrical

Ques:- You are given 220 V supply source, four wires, an ammeterand voltmeter. There is no any indication or description onmeters. How will you identify which is ammeter or voltmeter?

Asked In :-

Right Answer:
To identify the ammeter and voltmeter, connect the wires to the 220 V supply.

1. Connect two wires to the voltmeter. If it shows a reading, it is the voltmeter.
2. Connect the remaining two wires to the ammeter. If it shows a reading, it is the ammeter.

The device that shows a reading when connected across the supply is the voltmeter, and the one that shows a reading when connected in series is the ammeter.

Design Engineer - Electrical Electrical

Ques:- Where do we adjust the setting of thermal over load relay & how cal calulate.

Asked In :- subsea 7, alstom, mahathi infra services pvt. ltd.,

Right Answer:
The setting of a thermal overload relay is adjusted based on the full-load current (FLC) of the motor it protects. To calculate the setting, use the formula:

Setting (A) = FLC x 0.8 to 1.1 (depending on the motor's service factor).

Adjust the relay to the calculated value to ensure proper protection.

Design Engineer - Electrical Electrical

Ques:- Why secondary terminal of current transformer should not beopen circuited?

Asked In :- lec,

Right Answer:
Opening the secondary terminal of a current transformer can cause a high voltage to develop across the terminals, which can damage the transformer and pose a safety hazard.

Design Engineer - Electrical Electrical

Ques:- Suppose an electric motor with a controller is not working. What is the sequence of testing you will do in your troubleshooting?

Asked In :- Vestas Wind Technology India, EPC Projects, whirlpool,

Right Answer:
1. Check power supply: Ensure the motor is receiving the correct voltage and current.
2. Inspect connections: Look for loose or damaged wiring and connectors.
3. Test the controller: Verify that the controller is functioning properly and check for error codes.
4. Measure motor resistance: Use a multimeter to check the motor windings for continuity and shorts.
5. Check for mechanical obstructions: Ensure the motor shaft is not blocked or jammed.
6. Test the motor: If possible, connect the motor directly to a power source to see if it runs.
7. Review control signals: Check if the controller is sending the correct signals to the motor.

Comments

DK BOSS Jul 15, 2021

First, check the power supply switch position then check connections properly in switch-off condition. Smell and touch components whether heated or not. After that replace the motor to identify the fault.

Admin Oct 18, 2020

* 1st check the power supply switch whether on or off
* then Check the all wiring connections may be wire disconnected or there is any loose connection(OFF the switch).
* smell the component whether it is heated or not and touch to experiance the heat(OFF the switch).
* replace the controller/motor with new one to detect fault present in which part.

Design Engineer - Electrical Electrical

Ques:- How electrical power(MW)is varied OF an A.C Generator in response to varying steam input to a steam turbine ?

Asked In :- TUV SUD,

Right Answer:
The electrical power (MW) output of an AC generator varies with the steam input to a steam turbine by adjusting the turbine's steam flow. Increasing steam input raises the turbine's rotational speed, which in turn increases the generator's output power. Conversely, reducing steam input decreases the turbine speed and lowers the power output. The relationship is generally proportional, as long as the generator operates within its design limits.

Design Engineer - Electrical Electrical

Ques:- How to calculat the size of copper& aluminium wire ?

Asked In :- aci,

Right Answer:
To calculate the size of copper and aluminum wire, use the following formula:

1. **Determine the current (I)** in amperes that the wire will carry.
2. **Select the allowable voltage drop (Vd)**, typically 2-5% of the supply voltage.
3. **Use the formula:**

[
A = frac{(2 times L times I times R)}{Vd}
]

Where:
- (A) = cross-sectional area in mm²
- (L) = one-way length of the wire in meters
- (R) = resistivity of the material (for copper, approximately 0.0175 ohm·mm²/m; for aluminum, approximately 0.0282 ohm·mm²/m)

4. **Choose the wire gauge** based on the calculated area, referring to standard wire gauge charts for copper and aluminum.

Design Engineer - Electrical Electrical

Ques:- How to wiring 20 hp motor get completated?

Asked In :- Tmeic International Corporation,

Right Answer:
To wire a 20 HP motor, follow these steps:

1. **Select the Right Cable**: Use appropriate gauge wire based on the motor's voltage and distance from the power source.
2. **Install a Motor Starter**: Use a motor starter with overload protection suitable for a 20 HP motor.
3. **Connect Power Supply**: Connect the three-phase power supply to the motor starter input terminals.
4. **Connect Motor Leads**: Connect the motor leads (U, V, W) to the output terminals of the motor starter.
5. **Ground the Motor**: Ensure the motor is properly grounded to prevent electrical hazards.
6. **Control Circuit**: Wire the control circuit to the starter, including start/stop buttons.
7. **Check Connections**: Verify all connections are secure and correct.
8. **Test the Motor**: Power on the system and test the motor for proper operation.

Always follow local electrical codes and safety standards.

Design Engineer - Electrical Electrical

Ques:- How calculate gd2 of ht motors

Asked In :- yorkshire water, cfm, torc robotics,

Right Answer:
To calculate the GD² (Moment of Inertia) of high tension (HT) motors, use the formula:

[ GD² = frac{(P times 60)}{(2 pi N)} ]

Where:
- ( P ) = Power in watts
- ( N ) = Speed in RPM

Ensure to convert the power to the appropriate units if necessary.

Design Engineer - Electrical Electrical

Ques:- What is wet bulb and dry bulp temp. in air conditioner, why we use it.

Asked In :- alstom,

Right Answer:
Wet bulb temperature is the lowest temperature that can be achieved by evaporating water into the air, while dry bulb temperature is the air temperature measured by a regular thermometer. We use these temperatures in air conditioning to assess humidity levels and determine the efficiency of cooling systems.

Design Engineer - Electrical Electrical

Ques:- What is static Device & Mechanical device? Is transformer a static device?

Asked In :- Tube Investments of India, starfish medical,

Right Answer:
A static device is one that does not have moving parts and operates based on electromagnetic principles, such as a transformer. A mechanical device, on the other hand, involves moving parts and mechanical motion. Yes, a transformer is a static device.

Design Engineer - Electrical Electrical

Ques:- What is consistency transmitter and describe its working?

Asked In :- south32, paharpur cooling towers,

Right Answer:
A consistency transmitter is a device used in industrial processes to measure the concentration or consistency of a fluid, typically in applications like pulp and paper, food and beverage, or chemical processing. It works by using sensors to detect the properties of the fluid, such as its density or viscosity, and then converts this information into an electrical signal that can be transmitted to a control system for monitoring and control purposes.

Design Engineer - Electrical Electrical

Ques:- I want to calibrate a transmitter in the range of -100 to 300 mmwc. How it is possible to measure -100 to 300?.

Asked In :- Skyworks Solutions, ndf,

Right Answer:
To calibrate a transmitter for the range of -100 to 300 mmwc, you can use a dual-range calibration approach. Set the transmitter to measure negative pressure (from -100 mmwc to 0 mmwc) using a reference vacuum source, and then calibrate it for positive pressure (from 0 mmwc to 300 mmwc) using a pressure source. Ensure that the transmitter is capable of handling both negative and positive ranges, and adjust the zero and span settings accordingly during calibration.

Design Engineer - Electrical Electrical

Ques:- Will The Rated Capacity of 20 MVA ,220/6.6 KV, ONAN cooling Power Tranformer be increased up to 25 MVA with respect to its %Impedence by ONAF cooling with same rating..?

Asked In :- Pod Point, Engineering Component Solution,

Right Answer:
No, the rated capacity of the transformer cannot be increased from 20 MVA to 25 MVA simply by changing the cooling method from ONAN to ONAF. The transformer's capacity is primarily determined by its design and insulation, not just the cooling method.

Design Engineer - Electrical Electrical

Ques:- Why universal motor work on ac & dc both?

Asked In :- Ramboll India, Delta India Electronics, RDC Concrete (India), Virgo Engineers, walton group,

Right Answer:
A universal motor works on both AC and DC because its design allows the direction of current in the armature and field windings to change with the supply voltage, enabling it to operate efficiently on either type of current.

Design Engineer - Electrical Electrical

Ques:- What is the healthy specific gravity of lead acid battery used in DG sets ?

Asked In :- Wonder Cement, nasa,

Right Answer:
The healthy specific gravity of a lead-acid battery used in DG sets is typically between 1.265 and 1.300.

Design Engineer - Electrical Electrical

Ques:- Where AVR is connected in power plant.

Asked In :- sse plc, terrapower llc,

Right Answer:
AVR (Automatic Voltage Regulator) is connected to the generator in a power plant.

Design Engineer - Electrical Electrical

Ques:- Why NGR is required for 11Kv geneartor in power plant

Asked In :- Steel Dynamics, saudi electricity company, solaredge technologies, yarra trams, oz minerals,

Right Answer:
NGR (Neutral Grounding Resistor) is required for an 11kV generator in a power plant to limit the fault current during a ground fault, protect the generator and associated equipment from damage, and ensure safe operation by maintaining system stability.

Design Engineer - Electrical Personal Questions round

Ques:- Do you think you are u fit for this job

Asked In :- Sea Blue Shipyard,

Right Answer:
Yes, I believe I am fit for this job because I have the necessary skills, experience, and passion for electrical design engineering.

The Design Engineer – Electrical category on takluu.com is tailored for professionals and aspirants aiming to excel in electrical design roles. Electrical design engineers are responsible for planning, developing, and validating electrical systems for various applications, including power distribution, control systems, and electronics.

This section covers essential topics such as electrical circuit design, schematic diagrams, CAD software (like AutoCAD Electrical), wiring layouts, load calculations, and compliance with standards like IEC and NEC. You’ll also find questions related to design optimization, troubleshooting, protective devices, and safety protocols.

Interview questions often explore practical scenarios, for example:

“How do you approach designing a power distribution system?”
“Explain the use of AutoCAD Electrical in schematic design.”
“What factors do you consider for electrical load calculations?”

Our content presents complex design concepts in a clear and concise manner, supported by real-world examples and best practices. Whether you are fresh in the field or an experienced engineer, this category helps you prepare confidently for technical interviews and project discussions.

At Takluu, we keep this category updated with the latest tools, software advancements, and industry trends, ensuring you stay current and competitive in the electrical design domain.

Questions in: Design Engineer - Electrical

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