Indian Oil Corporation Electrical Supervisor Interview Questions and Answers for Experienced

A dropout switch is an electrical switch that opens when the voltage drops below a certain level.

• It is used to protect electrical equipment from damage due to low voltage.

• It can be manually or automatically reset.

• Examples include low voltage disconnect switches and thermal overload switches.

• It is commonly used in battery systems to prevent over-discharge.

• It is also used in power distribution systems to prevent damage t

A diode is an electronic component that allows current to flow in only one direction.

• It has two terminals, an anode and a cathode.

• It is commonly used in rectifiers to convert AC to DC.

• It can also be used as a voltage regulator or a signal modulator.

• It is made of semiconductor materials such as silicon or germanium.

• It has a forward voltage drop that varies depending on the material and temperature.

HRC fuse stands for High Rupturing Capacity fuse. It is a type of fuse that can withstand high fault currents.

• HRC fuse is designed to protect electrical equipment from overcurrents.

• It has a high breaking capacity and can interrupt high fault currents without causing damage to the equipment.

• HRC fuse is commonly used in industrial and commercial applications.

• It is available in different sizes and ratings to suit differen...read more

The RPM of a 4 pole motor is determined by the frequency of the power supply and the number of poles.

• The RPM of a 4 pole motor is directly proportional to the frequency of the power supply.

• The RPM of a 4 pole motor is inversely proportional to the number of poles.

• For example, a 4 pole motor connected to a 60 Hz power supply will have an RPM of approximately 1800.

• If the power supply frequency is increased to 120 Hz, the...read more

Yes, 10 kW is equal to 13.41 HP.

• 1 kW = 1.34 HP

• Therefore, 10 kW = 10 x 1.34 = 13.41 HP

• Conversion formula: HP = kW x 1.34

An isolator is an electrical switch that isolates a part of the circuit from the rest for maintenance or safety purposes.

• Isolators are used to disconnect a circuit from the power source.

• They are often used in high voltage applications.

• Isolators are different from circuit breakers or fuses, as they do not provide protection against overloads or short circuits.

• They are commonly used in industrial settings and power distr...read more

DC voltage is a constant voltage while AC voltage changes direction periodically.

• DC voltage is a steady voltage that flows in one direction only

• AC voltage changes direction periodically and has a frequency measured in Hertz

• DC voltage is commonly used in batteries and electronic devices

• AC voltage is used in household power outlets and electrical grids

A motor's speed can be controlled by a variable frequency drive (VFD).

• A VFD can adjust the frequency of the electrical power supplied to the motor, which in turn controls its speed.

• VFDs are commonly used in industrial settings to control the speed of motors powering machinery.

• VFDs can also improve energy efficiency by reducing the amount of power consumed by the motor.

• Other methods of controlling motor speed include us...read more