HCLTech Electrical Maintenance Engineer Interview Questions and Answers

An automatic door opening project using IR sensor.

• IR sensor detects motion and sends signal to microcontroller

• Microcontroller activates motor to open door

• Door closes after a set time or when sensor detects no motion

• Can be used in public places, hospitals, and homes

A circuit is a closed loop of conductive material that allows electricity to flow. A switch is a device that controls the flow of electricity in a circuit.

• A circuit is made up of a power source, conductive material, and a load.

• Electricity flows from the power source through the conductive material and into the load.

• A switch is used to open or close the circuit, controlling the flow of electricity.

• Switches can be manual...read more

MCB is a type of source of electrical energy used for protection against overload and short circuit.

• MCB stands for Miniature Circuit Breaker.

• It is a device that automatically switches off the electrical circuit during abnormal conditions such as overload or short circuit.

• MCBs are commonly used in residential, commercial, and industrial electrical installations.

• They provide protection to electrical equipment and prevent...read more

BigInteger is used for mathematical operations involving very large integers in Java.

• BigInteger is used when the range of values supported by primitive data types like int and long is not sufficient.

• It is commonly used in cryptography and security applications.

• It provides methods for arithmetic, bitwise, and logical operations on large integers.

• Example: calculating factorial of a large number, generating large prime nu

Merge Sort Algo code in java

• Divide the array into two halves

• Recursively sort the two halves

• Merge the sorted halves

• Time complexity: O(n log n)