500+ Diploma Trainee Engineer Interview Questions and Answers

Kirchhoff's Current Law states that the algebraic sum of currents meeting at a point in an electrical network is zero.

• Kirchhoff's Current Law is also known as the junction rule.

• It is based on the principle of conservation of charge.

• The law applies to both DC and AC circuits.

• It is used to analyze and solve complex electrical circuits.

• An example of applying Kirchhoff's Current Law is when determining the current flowing through different branches of a parallel circuit.

Electrical CAD is used to design and document electrical systems. Perpendicularity symbol is drawn using CAD tools.

• Electrical CAD helps in creating accurate and detailed electrical designs

• It allows for easy modification and updating of designs

• CAD tools can be used to draw symbols for various electrical components and properties

• To draw the symbol of perpendicularity, use the CAD tool for drawing lines and add a small square at the intersection of the lines

• The perpendicularity ...read more

Possible reasons for heavy white smoke

• Burning of coolant in the engine

• Leaking head gasket

• Faulty fuel injectors

• Burning of transmission fluid

• Excessive condensation in the exhaust system

Tata Cummins engines are of two types - B and C series.

• Tata Cummins engines are manufactured by Tata Motors and Cummins Inc.

• B series engines are 3.9L to 5.9L in displacement and are used in light and medium-duty vehicles.

• C series engines are 8.3L to 15L in displacement and are used in heavy-duty vehicles.

• Tata Cummins engines are known for their fuel efficiency and reliability.

Before replacing a fuse, one should take certain precautions to ensure safety.

• Ensure that the power supply is turned off before replacing the fuse.

• Identify the correct type and rating of the fuse to be replaced.

• Use appropriate safety equipment such as insulated gloves and goggles.

• Inspect the fuse holder for any signs of damage or overheating.

• Check for any underlying issues that may have caused the fuse to blow.

• Follow the manufacturer's instructions and guidelines for fuse rep...read more

A jig is a tool used to guide and control the movement of a cutting tool, while a fixture is used to hold and position a workpiece during machining.

• Jigs are used to guide the cutting tool, while fixtures hold the workpiece.

• Jigs are used in drilling, reaming, and tapping operations, while fixtures are used in milling, grinding, and turning operations.

• Jigs are often custom-made for specific operations, while fixtures can be standardized and reused.

• Jigs are typically more comple...read more

The types of materials used in engines vary depending on the specific engine type and its components.

• Engines can be made of various materials such as cast iron, aluminum, steel, and alloys.

• Different engine parts may require different materials, for example, pistons are often made of aluminum alloy.

• Engine components like cylinder heads, crankshafts, and connecting rods can be made of cast iron or steel.

• Some engines may also use specialized materials like carbon fiber for light...read more

G-code and M-code are programming languages for controlling CNC machines like mills, lathes, and 3D printers.

• G-code commands control the movement of the machine, such as G0 for rapid positioning and G1 for linear interpolation.

• M-code commands manage machine functions, like M3 for starting the spindle and M8 for turning on the coolant.

• G-code is primarily used for defining tool paths, while M-code is used for auxiliary functions.

• Example of G-code: G01 X10 Y10 F100 (move to coor...read more

Switchgear is essential for controlling, protecting, and isolating electrical equipment in power systems.

• Protection: Switchgear protects electrical circuits from faults like short circuits and overloads.

• Control: It allows for the control of electrical circuits, enabling safe operation and maintenance.

• Isolation: Switchgear provides isolation of equipment for safe inspection and maintenance.

• System Stability: It helps maintain voltage and current levels, ensuring stable operatio...read more

AC can be converted to DC using a rectifier circuit. The circuit diagram includes a transformer, diodes, and a filter capacitor.

• AC to DC conversion is achieved using a rectifier circuit.

• A rectifier circuit consists of a transformer, diodes, and a filter capacitor.

• The transformer steps down the AC voltage to a lower level.

• Diodes are used to convert the AC voltage to pulsating DC.

• The filter capacitor smoothens the pulsating DC to obtain a steady DC output.

• The circuit diagram ca...read more

Rectifier, types of motor, difference between servo motor and induction motor

• Rectifier is an electrical device that converts alternating current (AC) to direct current (DC)

• Types of motors include DC motors, AC motors, servo motors, and induction motors

• Servo motors are used in applications that require precise control of position, velocity, and acceleration

• Induction motors are commonly used in industrial applications due to their robustness and simplicity

• Difference between ser...read more

Major specifications to consider when buying an AC include cooling capacity, energy efficiency, noise level, and brand reputation.

• Cooling capacity measured in BTUs or tons

• Energy efficiency rating like EER or SEER

• Noise level in decibels

• Brand reputation for reliability and customer service

A phase diagram is a graphical representation of the relationships between different phases of a substance at different conditions.

• A phase diagram shows the boundaries between different phases (solid, liquid, gas) of a substance as a function of temperature and pressure.

• It helps in understanding the conditions under which a substance exists in different phases.

• Phase diagrams can also indicate the presence of phase transitions, such as melting, boiling, and sublimation.

• The dia...read more

There are various operations that can be performed on a lathe machine, including turning, facing, drilling, boring, knurling, and threading.

• Turning - used to create cylindrical parts

• Facing - used to create a flat surface at the end of a workpiece

• Drilling - used to create holes in the workpiece

• Boring - used to enlarge existing holes

• Knurling - used to create a textured pattern on the surface of the workpiece

• Threading - used to create threads on the workpiece

Diesel engines use compression ignition while petrol engines use spark ignition.

• Diesel engines use compression ignition while petrol engines use spark ignition

• Diesel engines are more fuel efficient than petrol engines

• Petrol engines generally have higher power output compared to diesel engines

• Diesel engines have higher torque at lower RPMs

• Diesel engines are typically more durable and have longer lifespans than petrol engines

A lathe machine shapes materials by rotating the workpiece and using a cutting tool to create symmetrical designs.

• Used for turning, drilling, and threading operations.

• Commonly used in metalworking to create parts like shafts and gears.

• Can also work with wood for making furniture or decorative items.

• CNC lathes offer automated precision for complex designs.

A resistor is an electronic component that limits the flow of electric current in a circuit.

• Resistors are used to control the amount of current flowing through a circuit.

• They are passive components that dissipate energy in the form of heat.

• Resistors are measured in ohms (Ω) and have color-coded bands to indicate their resistance value.

• They can be fixed resistors with a specific resistance value or variable resistors that can be adjusted.

• Resistors are commonly used in voltage ...read more

Power transmission is the transfer of mechanical energy within machines or systems to perform work efficiently.

• Involves components like gears, belts, and shafts to transfer energy.

• Used in vehicles to transmit engine power to wheels (e.g., drivetrain).

• Hydraulic systems use fluid power transmission for heavy machinery (e.g., excavators).

• Electrical power transmission involves moving electrical energy over distances (e.g., power lines).

• Applications include manufacturing equipment...read more

Four stroke engines have separate intake, compression, power, and exhaust strokes, while two stroke engines combine these strokes.

• Four stroke engines have a longer cycle and require more parts than two stroke engines.

• Four stroke engines are more fuel efficient and produce less pollution than two stroke engines.

• Two stroke engines are simpler in design and have a higher power-to-weight ratio than four stroke engines.

• Two stroke engines are commonly used in small power tools and ...read more

A transformer is an electrical device that transfers electrical energy from one circuit to another through electromagnetic induction.

• Transformers are used to either step up or step down voltage levels.

• Step down transformers decrease voltage levels, while step up transformers increase voltage levels.

• Types of transformers include power transformers, distribution transformers, isolation transformers, autotransformers, and instrument transformers.

• Power transformers are used in po...read more

Backward stroke is the return stroke of the ram in shaping machine, while forward stroke is the cutting stroke.

• Backward stroke is when the ram moves away from the workpiece

• Forward stroke is when the ram moves towards the workpiece to make the cut

• Backward stroke is non-cutting, while forward stroke is cutting

• Backward stroke allows the tool to clear the workpiece, while forward stroke performs the cutting operation

Mechanical engineering deals with designing and manufacturing mechanical systems, while Automobile engineering focuses on designing and manufacturing vehicles.

• Mechanical engineering involves designing and manufacturing various mechanical systems such as engines, HVAC systems, and manufacturing equipment.

• Automobile engineering specifically focuses on designing and manufacturing vehicles like cars, motorcycles, and trucks.

• Mechanical engineers work on a wide range of projects be...read more

List of 100 questions from favourite technical subject

• What is the purpose of a heat exchanger?

• Explain the difference between a centrifugal pump and a reciprocating pump.

• How does a PID controller work in a control system?

• What is the difference between stress and strain in materials?

• Explain the concept of Ohm's Law in electrical circuits.

• What is the function of a capacitor in an electronic circuit?

• Describe the operation of a diesel engine.

• What are the different types of welding...read more

CTs measure current, while PTs measure voltage in electrical systems for protection and metering.

• CTs are used to step down high current levels to a manageable value for measurement.

• PTs are used to step down high voltage levels to a lower value for measurement.

• Example of CT: Used in power plants to monitor generator output.

• Example of PT: Used in substations to monitor line voltage.

• CTs provide current input for protective relays, while PTs provide voltage input.

Steam in a boiler is generated by heating water to its boiling point. There are various types of boilers, such as fire tube, water tube, and electric boilers.

• Boilers generate steam by heating water to its boiling point

• Types of boilers include fire tube, water tube, and electric boilers

• Fire tube boilers have hot gases flowing through tubes that are surrounded by water

• Water tube boilers have water flowing through tubes that are heated by combustion gases

• Electric boilers use ele...read more

PNP and NPN transistors are two types of bipolar junction transistors with opposite polarity.

• PNP has a layer of N-type semiconductor sandwiched between two layers of P-type semiconductor, while NPN has a layer of P-type semiconductor sandwiched between two layers of N-type semiconductor.

• In PNP, the current flows from the emitter to the base and then to the collector, while in NPN, the current flows from the emitter to the collector through the base.

• PNP is used in high-side sw...read more

CNC stands for Computer Numerical Control and VMC stands for Vertical Machining Center. Mechanical engineering involves designing, analyzing, and manufacturing mechanical systems. Manufacturing is the process of converting raw materials into finished products, while production refers to the overall process of creating goods.

• CNC is a manufacturing process that uses computerized controls to operate machine tools.

• VMC is a type of CNC machine that operates in a vertical orientati...read more