Wapcos Service Engineer Interview Questions and Answers

Precommissioning tests of transformers ensure proper functioning and safety before energizing.

• Visual inspection of transformer and its components

• Measurement of insulation resistance

• Measurement of winding resistance

• Verification of transformer ratio and polarity

• Verification of oil level and quality

• Testing of protective devices

• Verification of grounding

• Functional testing of cooling system

• Verification of nameplate data

11kv & 33kv overhead power line distribution

• 11kv and 33kv are common voltage levels for overhead power lines

• Overhead power lines are used to distribute electricity from power stations to consumers

• The voltage level determines the distance the power can be transmitted and the size of the conductors needed

• Proper insulation and grounding is important for safety

• Maintenance and inspection of the lines is necessary to ensure

Initial setting time of cement is the time taken by cement to harden and attain a particular strength.

• Initial setting time is determined by Vicat apparatus

• It is the time taken for the cement to lose its plasticity and become hard

• The standard initial setting time for ordinary Portland cement is 30 minutes

• Factors affecting initial setting time include temperature, water-cement ratio, and type of cement

The elongation % of steel fy 500 is approximately 12%.

• Elongation % is the measure of ductility of a material.

• It is the percentage increase in length of a material before it fractures under tension.

• For steel fy 500, the elongation % is approximately 12%.

• This means that the steel can stretch up to 12% of its original length before it breaks.

The amount of cement required for 1 cubic meter varies depending on the concrete mix design.

• The amount of cement needed for 1 cubic meter of concrete varies from 250kg to 600kg depending on the mix design.

• The mix design specifies the ratio of cement to other materials like sand and aggregates.

• For example, a mix design of 1:2:4 requires 400kg of cement per cubic meter of concrete.

• It is important to accurately calculate ...read more

Density of materials: Steel - 7850 kg/m3, Concrete - 2400 kg/m3, Sand - 1600 kg/m3

• Density of steel is higher than that of concrete and sand

• Density of concrete varies depending on the mix design

• Density of sand can vary depending on the source and moisture content