Bharat Petroleum Mumbai Refinery Electrical Supervisor Interview Questions and Answers

Star-Delta starter is used to start 3-phase motors. It reduces the starting current and torque.

• Star-Delta starter connects the motor in star configuration during starting to reduce the starting current and torque.

• After a few seconds, the starter switches the motor to delta configuration for normal operation.

• This method is used for motors with high starting current and torque requirements.

• It is commonly used in industri...read more

DOL starter is a direct-on-line starter used to start 3-phase motors by connecting them directly to the power supply.

• DOL starter provides full voltage to the motor at the start

• It consists of a contactor, overload relay, and start/stop push buttons

• The contactor connects the motor to the power supply

• The overload relay protects the motor from overloading

• The start/stop push buttons control the on/off function of the motor

The unit of Energy is Joule (J)

• The unit of Energy is Joule (J)

• Energy can also be measured in kilowatt-hours (kWh)

• 1 Joule is equal to 1 watt-second

The unit of resistance is Ohm (Ω).

• The unit of resistance is represented by the symbol Ω (Ohm).

• Resistance is measured in Ohms, named after the German physicist Georg Simon Ohm.

• One Ohm is equal to one volt per ampere (1 Ω = 1 V/A).

The unit of current is Ampere (A)

• The unit of current is Ampere (A)

• Current is the flow of electric charge in a circuit

• 1 Ampere is equivalent to 1 Coulomb per second

• Current is measured using an ammeter

The unit of capacitance is Farad (F)

• The unit of capacitance is named after Michael Faraday

• 1 Farad is equal to 1 Coulomb per Volt

• Common multiples of Farad include microfarad (uF) and picofarad (pF)

The unit of power is the watt (W)

• The unit of power is the watt (W)

• Power is the rate at which work is done or energy is transferred

• 1 watt is equal to 1 joule per second

• Common examples of power units include kilowatts (kW) and horsepower (hp)

The unit of power is the watt (W).

• The unit of power is the watt (W)

• Power is the rate at which work is done or energy is transferred

• 1 watt is equal to 1 joule per second

• Common examples of power units include kilowatts (kW) and horsepower (hp)

The unit of current is Ampere (A), which measures the rate of flow of electric charge.

• The unit of current is Ampere (A)

• Current is the rate of flow of electric charge

• Commonly represented by the symbol 'I'

• 1 Ampere is equivalent to 1 Coulomb per second