Draftsman/ Draughtsman - Electrical Interview Questions and Answers in 2025 (100+ Q&A)

Draftsman/ Draughtsman - Electrical Electrical

Ques:- What is a bus post insulator? explain its application in a substation.

Asked In :- Mahindra Tractors, SasMos HET Technologies,

Right Answer:
A bus post insulator is a type of electrical insulator used to support and insulate busbars in substations. It prevents electrical current from leaking to the ground while allowing the busbars to remain securely in place. Its application in a substation is to ensure safe and reliable operation by isolating the busbars from the supporting structures, thereby maintaining the integrity of the electrical system.

Draftsman/ Draughtsman - Electrical Electrical

Ques:- The corona effect is more ina) summer b) winter c) dry weather d)humidity weather

Asked In :- hindalco industries limited,

Right Answer:
c) dry weather

Draftsman/ Draughtsman - Electrical Electrical

Ques:- What is LOP Sensor in DG??????

Asked In :- Greentech Industries (INDIA), scania,

Right Answer:
LOP Sensor in DG (Diesel Generator) stands for Low Oil Pressure Sensor. It monitors the oil pressure in the engine and triggers an alarm or shutdown if the pressure falls below a safe level to prevent engine damage.

Draftsman/ Draughtsman - Electrical Electrical

Ques:- What is Diff. btw Cat-5 & Cat-6 Network Cables???

Asked In :- Altran Group,

Right Answer:
Cat-5 cables support speeds up to 100 Mbps and frequencies up to 100 MHz, while Cat-6 cables support speeds up to 10 Gbps and frequencies up to 250 MHz.

Draftsman/ Draughtsman - Electrical Electrical

Ques:- How capacitor active and reactive.

Asked In :- Recaero, Great Wall Motor Company, sunway group,

Right Answer:
A capacitor is considered active when it stores energy in the electric field between its plates, and it is reactive because it does not consume power but instead alternately absorbs and releases energy in the circuit, contributing to reactive power.

Draftsman/ Draughtsman - Electrical Electrical

Ques:- WHY WE NOT USE 2-20mA,1-20mA,3-20mA or 10-50mA SIGNAL? INSTEAD OF 4-20mA.

Asked In :- western power,

Right Answer:
We use 4-20mA signals instead of 2-20mA, 1-20mA, 3-20mA, or 10-50mA because the 4-20mA range allows for a clear distinction between the zero signal (4mA) and the failure condition (0mA). This helps in detecting faults and ensures better accuracy and reliability in signal transmission over long distances.

Draftsman/ Draughtsman - Electrical Electrical

Ques:- Induction motor. we have a three phase supply from diffrent source like R= transformer. Y = DG sets. B = ups. if motor is runing.

Asked In :-

Right Answer:
If an induction motor is running on a three-phase supply from different sources (transformer, DG sets, UPS), it is crucial to ensure that the phase sequence and voltage levels are compatible to avoid damage to the motor and ensure proper operation.

Draftsman/ Draughtsman - Electrical Electrical

Ques:- When an induction motor runs on load.at that time if we reduce the supply voltage the current increases.But when it runs without load,if we reduce the supply voltage the current also reduced.why?.i checked it practically also.

Asked In :- royal jet, evergy, ola,

Right Answer:
When an induction motor runs on load and the supply voltage is reduced, the motor draws more current to maintain the required torque. However, when it runs without load, reducing the supply voltage decreases the current because there is less demand for power, and the motor operates more efficiently at a lower voltage.

Draftsman/ Draughtsman - Electrical Electrical

Ques:- How we detect the leakage current of 11 KV H.T. motors and waht is the maximim limit?

Asked In :- Tube Investments of India,

Right Answer:
Leakage current in 11 KV H.T. motors can be detected using an insulation resistance tester (megger) or a clamp meter designed for leakage current measurement. The maximum limit for leakage current is typically 5 mA, but it can vary based on specific standards and manufacturer recommendations.

Draftsman/ Draughtsman - Electrical Electrical

Ques:- If we give 60 hz single phase supply to the transformer usedin europe , than what will happen

Asked In :- Rocket Lab, ve commercial vehicles limited (a volvo group and eicher motors joint venture),

Right Answer:
If you give a 60 Hz single-phase supply to a transformer designed for Europe (which typically operates at 50 Hz), it may overheat, operate inefficiently, and potentially get damaged due to the increased magnetic flux and core saturation.

Draftsman/ Draughtsman - Electrical Personal Questions round

Ques:- Why are you looking for a change with in three months exp inpresent company?

Asked In :- McDermott, Aarav Unmanned Systems,

Right Answer:
I am looking for a change because I want to find a position that better aligns with my career goals and offers opportunities for growth and development in my field.

Draftsman/ Draughtsman - Electrical Personal Questions round

Ques:- Which is your dream company and why?

Asked In :-

Right Answer:
My dream company is [Company Name] because it is known for its innovative projects and commitment to sustainability in electrical engineering, which aligns with my career goals and values.

Draftsman/ Draughtsman - Electrical Electrical

Ques:- I have 2 motor of same rating. on no load condition one motor take 1.6A but other motor is taking 4.8A. what is the reason of this. please explain with proof.

Asked In :- Dxcorr Hardware Technologies, moschip semiconductor,

Right Answer:
The difference in no-load current between the two motors can be attributed to factors such as winding resistance, core losses, and mechanical issues. The motor taking 4.8A may have higher winding resistance, poor insulation, or magnetic losses due to core saturation or defects. Additionally, it could indicate that the motor is not properly designed or has internal faults, such as shorted turns in the winding.

Draftsman/ Draughtsman - Electrical Electrical

Ques:- Why sec of ct should be kept shorted

Asked In :- gb railfreight,

Right Answer:
The secondary of a current transformer (CT) should be kept shorted to prevent high voltage from developing across the terminals, which can cause insulation failure and pose safety hazards.

Draftsman/ Draughtsman - Electrical Electrical

Ques:- What is Specific Gravity of the Electrolyte used in Lead Acid Battery????What is Unit????

Asked In :- evergy,

Right Answer:
The specific gravity of the electrolyte used in a lead-acid battery is typically between 1.1 and 1.3. The unit is dimensionless, as it is a ratio of the density of the electrolyte to the density of water.

Draftsman/ Draughtsman - Electrical Electrical

Ques:- How is electricity converted from the potential energy of water falling from dams?

Asked In :- qinetiq, bangladesh air force, jtag technologies,

Right Answer:
Electricity is generated from the potential energy of falling water by using turbines. As water flows down from the dam, it turns the turbines, which are connected to generators that convert the mechanical energy of the turbines into electrical energy.

Draftsman/ Draughtsman - Electrical Electrical

Ques:- We are getting supply at33kvand it stepdown to 11kv.So Our requirement is 11kv voltage.why we draw 33kv from the grid instead of 11kv?

Asked In :- makati development corporation,

Right Answer:
We draw 33kV from the grid instead of 11kV because higher voltage transmission reduces power losses over long distances, making it more efficient to transport electricity before stepping it down to the required voltage.

Draftsman/ Draughtsman - Electrical Electrical

Ques:- What is the difference between Earthing,Grounding and neutral?

Asked In :- SMC Pneumatics, terrapower llc,

Right Answer:
Earthing refers to connecting the electrical system to the ground for safety, preventing electric shock. Grounding is a broader term that includes earthing but also refers to connecting equipment to a common reference point to stabilize voltage levels. Neutral is a conductor that carries current back to the source in an electrical system, completing the circuit.

Draftsman/ Draughtsman - Electrical Electrical

Ques:- What is the equation of insulating resistance of motor???

Asked In :- Sulzer Pumps, Fisher Chennai Engineering Centre,

Right Answer:
The equation for the insulation resistance (R) of a motor is given by:

[ R = frac{V}{I} ]

where:
- ( R ) is the insulation resistance in ohms (Ω),
- ( V ) is the voltage applied (in volts),
- ( I ) is the leakage current (in amperes).

Draftsman/ Draughtsman - Electrical Electrical

Ques:- In case of 3Phase Supply, Voltage R-Earth/Neutral – 220 Y-Earth/Neutral – 220 Z-Earth/Neutral – 220 Total is -> 660VoltsThen Why it is said that 3Phase supply is 440

Asked In :- qatar petroleum, neste, vikram solar, toyota boshoku,

Right Answer:
In a 3-phase supply, the line-to-line voltage is 440 volts, while the line-to-neutral (or line-to-earth) voltage is 220 volts. The total voltage of 660 volts mentioned is not the correct way to describe the system; instead, it refers to the sum of the individual line-to-neutral voltages, which is not how 3-phase systems are typically calculated. The standard 3-phase voltage is defined by the line-to-line voltage, which is 440 volts.

The Draftsman / Draughtsman – Electrical category on takluu.com is tailored for technical aspirants preparing for roles in electrical layout, drafting, and design documentation. This category covers essential knowledge such as circuit diagrams, wiring layouts, single‑line schematics, earthing plans, and electrical installation standards (such as IEEE, IEC, NEC).

You’ll learn to handle AutoCAD Electrical, Revit, and other CAD tools, with sample questions about creating panel schedules, understanding bill of materials, cable routing conventions, and symbol usage. Practical interview topics include:

How to read and interpret electrical drawings
Creating load schedules and cable sizing
Difference between power and lighting layouts
Symbol standards and referencing in CAD drawings

Mock questions also involve real drafting scenarios such as modifying IS-standard electrical layouts, annotating drawings for safety compliance, and planning layouts for industrial or building installations.

Whether you’re interviewing for roles in engineering companies, construction firms, or manufacturing units, this category helps polish both technical skills and CAD proficiency to excel in job selection processes.

Questions in: Draftsman/ Draughtsman - Electrical

What makes Takluu valuable for interview preparation?

Get Our Mobile App

Programming

Reasoning

Network & Telecom

Management

What makes Takluu valuable for interview preparation?