10+ Tech Mahindra Interview Questions and Answers

Tap changer in a transformer is located on the high voltage winding side to regulate the voltage output.

• Tap changer is typically located on the high voltage winding side of a transformer.

• It is used to adjust the turns ratio and regulate the voltage output.

• If the voltage output in the secondary decreases, the tap changer will be moved to a higher tap position to increase the voltage.

Hipot testing is a process used to verify the insulation integrity of busbars, breakers, cables, and transformers.

• Hipot testing involves applying a high voltage to the component being tested.

• The purpose is to check for any insulation breakdown or leakage current.

• For busbars and cables, the test is typically performed between the conductor and the ground.

• For breakers and transformers, the test is performed between different terminals or windings.

• The test voltage is usually hig...read more

If battery polarity is inverse with respect to battery charger, it can lead to damage or malfunction.

• Inverse polarity can cause short circuits or overheating.

• It can damage the battery, charger, or both.

• Reverse polarity protection circuits can prevent damage.

• Always double-check the polarity before connecting the battery to the charger.

The hipot test can be done on a cable multiple times depending on the specific requirements and standards.

• The number of times a hipot test can be done on a cable depends on the cable's specifications and the testing requirements.

• Generally, a hipot test is performed once during the manufacturing process to ensure the cable's insulation integrity.

• However, additional hipot tests may be conducted during the cable's lifespan for maintenance or troubleshooting purposes.

• The frequenc...read more

I have handled various quality documents such as quality control plans, inspection reports, and non-conformance reports.

• Quality control plans

• Inspection reports

• Non-conformance reports

Tests done on power transformers include insulation resistance, turns ratio, winding resistance, and dielectric tests.

• Insulation resistance test checks the insulation quality of the transformer.

• Turns ratio test measures the ratio of primary to secondary turns.

• Winding resistance test determines the resistance of transformer windings.

• Dielectric tests assess the dielectric strength and insulation properties of the transformer.

• Other tests may include temperature rise, short-circu...read more

IR, WR, and CR are abbreviations used in different contexts. IR stands for Infrared, WR stands for Weather Resistant, and CR stands for Compression Ratio.

• IR refers to Infrared, which is a type of electromagnetic radiation with longer wavelengths than visible light.

• WR is used to indicate that a product or material is designed to withstand various weather conditions.

• CR is a term commonly used in engineering and physics to describe the ratio of the volume of a compressed substan...read more

There are several types of earthing used in electrical systems.

• The most common types of earthing are:

• - TN-S system: Separate neutral and protective earth conductors

• - TN-C system: Combined neutral and protective earth conductors

• - TN-C-S system: Combination of TN-S and TN-C systems

• - TT system: Separate earth electrode for each electrical installation

• - IT system: No direct connection between earth and neutral

• Each type of earthing has its own advantages and is used in different s...read more

Tests performed on PT include prothrombin time, international normalized ratio, and clotting factor assays.

• Prothrombin time (PT) measures the time it takes for blood to clot.

• International normalized ratio (INR) is a standardized measurement of PT used to monitor the effectiveness of anticoagulant therapy.

• Clotting factor assays are performed to identify deficiencies or abnormalities in specific clotting factors.

• Other tests like activated partial thromboplastin time (aPTT) and ...read more

Soil compaction testing involves using specialized equipment to measure the density and moisture content of soil.

• Use a soil compaction tester to measure the density of the soil.

• Take samples at different depths to ensure accurate results.

• Calculate the compaction percentage by comparing the field density to the maximum density.

• Check the moisture content of the soil to ensure it is within the acceptable range.

• Repeat the testing process in multiple locations to ensure consistency...read more

Criteria for cube testing include sample preparation, curing, testing age, and acceptance criteria.

• Sample preparation involves properly filling the cube mold with concrete and compacting it.

• Curing the cubes in a controlled environment for a specified period of time is crucial for accurate results.

• Testing age refers to the duration after which the cubes are tested, typically 7 or 28 days.

• Acceptance criteria vary based on the strength of concrete required for the project.

Count of tools in a Junior Engineer interview

• Vernier caliper - 1

• GD&T profile projector - 1

• Other tools - not specified