10+ Maa Saraswati Educational Trust Interview Questions and Answers

A circuit breaker is an electrical switch that automatically interrupts the flow of current in a circuit.

• Circuit breakers are used to protect electrical circuits from overloads, short circuits, and faults.

• They are designed to open and close the circuit under normal and abnormal conditions.

• Common types of circuit breakers include thermal, magnetic, and thermal-magnetic circuit breakers.

• Thermal circuit breakers use a bimetallic strip that bends when heated to open the circuit.

• M...read more

A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction.

• Transformers are used to increase or decrease the voltage in electrical power transmission and distribution systems.

• They consist of two or more coils of wire, known as windings, that are wound around a core made of magnetic material.

• The primary winding receives electrical energy from the input circuit and produces a magnetic field.

• This magnetic...read more

A generator is a device that converts mechanical energy into electrical energy.

• Generators work on the principle of electromagnetic induction.

• They consist of a rotor and a stator, with the rotor rotating inside the stator.

• The rotation of the rotor creates a magnetic field, which induces an electrical current in the stator windings.

• The electrical output of a generator can be AC or DC, depending on the design.

• Examples of generators include hydroelectric generators, wind turbines...read more

A starter is an electrical device that starts and stops a motor by providing the necessary power to it. The starter circuit is the electrical circuit that controls the starter.

• A starter is typically composed of a contactor, overload relay, and control circuit.

• The starter circuit includes components such as switches, relays, fuses, and wiring.

• The starter circuit is responsible for providing power to the starter and ensuring that the motor starts and stops safely.

• Starter circui...read more

MCB stands for Miniature Circuit Breaker. It is an electrical switch that automatically trips when the current exceeds its rating.

• MCB is a type of circuit breaker that is commonly used in residential and commercial buildings.

• It is designed to protect electrical circuits from damage caused by overloading or short circuits.

• The working principle of MCB is based on the thermal and magnetic properties of the materials used in its construction.

• When the current flowing through the M...read more

Preventive maintenance in electrical systems involves regular inspections, testing, and servicing to prevent equipment failures and ensure optimal performance.

• Regularly inspect electrical equipment for signs of wear, damage, or overheating.

• Perform routine testing and calibration of electrical systems to identify potential issues before they cause failures.

• Clean and lubricate electrical components to prevent dust buildup and ensure smooth operation.

• Replace worn-out or faulty p...read more

An air circuit breaker is an electrical device that provides protection against overcurrents by using air as the medium to extinguish the arc.

• Air circuit breakers work on the principle of thermal and magnetic tripping.

• When an overcurrent flows through the circuit, the bimetallic strip in the breaker heats up and bends, causing the contacts to open.

• The arc generated during the opening of contacts is extinguished by the blast of compressed air.

• Air circuit breakers are commonly ...read more

Power factor is a measure of how effectively electrical power is being converted into useful work output.

• Power factor is the ratio of real power to apparent power in an electrical circuit.

• It is a number between 0 and 1, with 1 representing perfect efficiency.

• A low power factor indicates that a circuit is not efficiently using the power it is receiving.

• Power factor can be improved by using power factor correction devices such as capacitors.

• Formula: Power Factor = Real Power / ...read more

A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction.

• Consists of two coils of wire, known as primary and secondary windings

• Operates on the principle of Faraday's law of electromagnetic induction

• Used to increase or decrease voltage levels in electrical circuits

• Commonly used in power distribution systems to step up or step down voltage

• Examples include power transformers, distribution transformers, ...read more

Power is the ability to influence or control others, or the capacity to perform effectively.

• Power can be in the form of authority, control, or influence over others.

• It can also refer to the ability to perform effectively or efficiently in a given task or role.

• Examples of power include political power, physical power, and expert power in a specific field.

The dg is a unit of measurement used in the field of optics to represent the diameter of a lens or aperture.

• dg stands for diameter

• It is commonly used in specifying the size of camera lenses, telescope apertures, and other optical components

• For example, a lens with a dg of 50mm has a diameter of 50 millimeters

A motor is a device that converts electrical energy into mechanical energy to produce motion.

• Converts electrical energy into mechanical energy

• Produces motion

• Common types include electric motors and combustion engines

ACB stands for Air Circuit Breaker, a type of circuit breaker that operates in the air as an arc extinguishing medium.

• ACB is used to protect electrical circuits from overloads and short circuits.

• It is commonly used in industrial and commercial applications.

• ACBs can be manually operated or automatically operated based on the current flow.

• Examples of ACB manufacturers include Siemens, Schneider Electric, and ABB.

VCB stands for Vacuum Circuit Breaker, a type of circuit breaker that uses vacuum as the arc quenching medium.

• VCB is used to interrupt fault currents in electrical systems.

• It operates by creating a vacuum between the contacts to extinguish the arc.

• VCBs are commonly used in medium voltage applications.

• They are preferred over other types of circuit breakers due to their compact size and maintenance-free operation.

UPS provides backup power during power outages while stabilizer maintains a constant voltage output.

• UPS stands for Uninterruptible Power Supply and provides backup power during power outages.

• Stabilizer maintains a constant voltage output and protects electrical equipment from voltage fluctuations.

• UPS is used for critical equipment like servers, medical equipment, etc. while stabilizer is used for household appliances like refrigerators, air conditioners, etc.

Losses in transformer refer to the energy lost in the form of heat during the process of transforming voltage.

• There are two types of losses in transformers: copper losses and iron losses.

• Copper losses occur due to the resistance of the wire used in the transformer's windings.

• Iron losses occur due to the magnetic properties of the transformer's core material.

• Copper losses can be reduced by using thicker wire or increasing the number of windings.

• Iron losses can be reduced by us...read more

UPS stands for Uninterruptible Power Supply.

• UPS is an electrical device that provides emergency power to a load when the input power source fails.

• It is commonly used to protect computers, servers, and other electronic equipment from power outages and voltage fluctuations.

• UPS can be classified into three types: standby, line-interactive, and online.

• Examples of UPS brands include APC, CyberPower, and Tripp Lite.