Fabrication Engineer Interview Questions and Answers

Rectifier converts AC to DC current in a welding machine.

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

• In a welding machine, rectifier is used to convert the AC power supply to DC power supply.

• DC power supply is required for welding as it provides a stable and consistent current.

• There are different types of rectifiers used in welding machines such as diode rectifiers, thyristor rectifiers, and transistor rectifiers.

Pneumatic systems use compressed air while hydraulic systems use pressurized liquid to transmit power.

• Pneumatic systems are generally cheaper and easier to maintain than hydraulic systems.

• Hydraulic systems can generate more force than pneumatic systems due to the incompressibility of liquids.

• Pneumatic systems are commonly used in industries such as food processing and packaging, while hydraulic systems are used in heavy machinery and construction equipment.

• Pneumatic systems a...read more

SI and CI engines are used in both 2-stroke and 4-stroke cycles, with differences in fuel injection and combustion processes.

• In a 2-stroke SI engine, the intake, compression, power, and exhaust strokes occur in two cycles of the piston, with fuel-air mixture being ignited by a spark plug.

• In a 4-stroke SI engine, the four strokes are separate and sequential, with fuel-air mixture being ignited by a spark plug in the combustion chamber.

• In a 2-stroke CI engine, the intake, compr...read more

A bore gauge is used to measure the diameter of a pipe bore.

• Bore gauge is a common instrument used for measuring pipe bore diameter.

• It consists of a gauge head with two or three arms that can be adjusted to fit inside the pipe.

• The gauge head is then locked in place and the measurement is taken using a micrometer or dial indicator.

• Other instruments that can be used include calipers and tape measures.

The least count of vernier caliper is the smallest measurement that can be read on the scale.

• The least count is determined by the number of divisions on the vernier scale and the main scale.

• For example, if the main scale has 10 divisions and the vernier scale has 9 divisions, the least count would be 1/10 x 1/9 = 0.111 mm.

• The least count can vary depending on the precision of the instrument.

• It is important to use the correct least count when taking measurements to ensure accu...read more

Vernier calipers are of two types - internal and external.

• Internal vernier caliper is used to measure the internal diameter of an object.

• External vernier caliper is used to measure the external diameter of an object.

• Both types have a main scale and a sliding vernier scale for precise measurements.

MIG welding stands for Metal Inert Gas welding, a process where a continuous solid wire electrode is fed through a welding gun.

• MIG welding uses a shielding gas to protect the weld from contaminants in the air.

• The wire electrode melts and joins the base materials together.

• Commonly used in automotive, construction, and manufacturing industries.

• Provides high welding speeds and can be used on a variety of metals.

SI and CI engines are types of internal combustion engines, with SI engines using spark plugs for ignition and CI engines using compression for ignition.

• SI engine stands for Spark Ignition engine, where fuel is ignited by a spark plug

• CI engine stands for Compression Ignition engine, where fuel is ignited by compression

• SI engines are commonly used in gasoline-powered vehicles

• CI engines are commonly used in diesel-powered vehicles