NTPC Apprenticeship Trainee Interview Questions, Process, and Tips

A circuit breaker is a device that automatically interrupts the flow of electric current in a circuit to protect against short circuits.

• Circuit breakers are designed to prevent damage to electrical equipment and wiring caused by excessive current.

• They work by detecting abnormal current flow and quickly opening the circuit to stop the flow of electricity.

• This helps to prevent overheating, fires, and other hazards that c...read more

Transformers are electrical devices that transfer energy from one circuit to another through electromagnetic induction.

• Transformers work by changing the voltage and current levels of an alternating current (AC) power supply.

• They consist of two coils of wire, called the primary and secondary windings, wrapped around a magnetic core.

• When an AC voltage is applied to the primary winding, it creates a magnetic field that in...read more

A motor is a machine that converts electrical energy into mechanical energy.

• Motors are used in various applications such as fans, pumps, and vehicles.

• There are two types of motors: AC motors and DC motors.

• AC motors are commonly used in household appliances while DC motors are used in electric vehicles.

• Motors work by using the interaction between a magnetic field and an electric current to produce motion.

• The speed of a ...read more

AC and DC currents are two types of electrical currents with different characteristics.

• AC (Alternating Current) is a type of electrical current that periodically changes direction.

• DC (Direct Current) is a type of electrical current that flows in only one direction.

• AC is commonly used in household electrical systems, while DC is used in batteries and electronic devices.

• AC current is generated by power plants and transmi...read more

The electric frequency in India is 50hz.

• Electricity in India operates at a frequency of 50hz.

• This is the same frequency used in most countries in Asia and Europe.

• The frequency is important for the proper functioning of electrical appliances.

A relay is an electrically operated switch that uses an electromagnet to mechanically open or close a circuit.

• Relays are commonly used in electrical systems to control high voltage or high current circuits with low voltage signals.

• They can be used for a variety of applications such as controlling lights, motors, and solenoids.

• Relays come in different types such as electromagnetic, solid-state, and reed relays.

• They are ...read more

AC electric current is a type of electrical current that periodically reverses direction.

• AC stands for Alternating Current

• It is commonly used in household appliances and power grids

• The voltage and frequency of AC current can vary depending on the application

• Examples of AC current include the power supply in your home and the electricity used to power electric motors

Solar energy is the energy obtained from the sun's radiation and converted into usable energy.

• Solar energy is renewable and sustainable.

• It is harnessed through the use of solar panels, which convert sunlight into electricity.

• Solar energy can be used for a variety of purposes, including powering homes and businesses, heating water, and even powering cars.

• It is a clean source of energy, producing no greenhouse gas emissi...read more

A control system is a system that manages, commands, directs, or regulates the behavior of other devices or systems.

• Control systems are used in various fields such as engineering, manufacturing, and automation.

• They can be either open-loop or closed-loop systems.

• Open-loop systems do not have feedback, while closed-loop systems use feedback to adjust their output.

• Examples of control systems include thermostats, cruise co...read more

Current can be measured using an ammeter.

• An ammeter is connected in series with the circuit to measure current.

• The ammeter should have a suitable range for the expected current.

• The circuit should be turned off before connecting the ammeter.

• The ammeter should be connected in the correct orientation.

• The reading on the ammeter should be recorded and interpreted correctly.

Voltage can be measured using a voltmeter or a multimeter.

• Connect the voltmeter/multimeter to the circuit or component being measured

• Set the range of the voltmeter/multimeter to the appropriate voltage level

• Read the voltage measurement displayed on the voltmeter/multimeter

• Ensure proper grounding and safety precautions are taken

• Examples of voltage measurements include measuring the voltage of a battery or power supply

Motor converts electrical energy into mechanical energy while generator converts mechanical energy into electrical energy. Buck converter steps down voltage while boost converter steps up voltage.

• Motor converts electrical energy into mechanical energy while generator converts mechanical energy into electrical energy

• Motor has a rotor and a stator while generator has a stator and a rotor

• Buck converter steps down voltage ...read more

VCB stands for Vacuum Circuit Breaker, a type of circuit breaker used in substations for switching and protecting electrical circuits.

• VCB uses vacuum as the arc quenching medium instead of oil or gas

• It is more efficient and requires less maintenance compared to traditional circuit breakers

• VCBs are commonly used in medium voltage applications in substations

• Example: ABB VD4 Vacuum Circuit Breaker

Power factor is the ratio of real power to apparent power. Transformer losses include copper losses, core losses, and stray losses.

• Power factor is a measure of how efficiently electrical power is being used.

• It is the ratio of real power (measured in watts) to apparent power (measured in volt-amperes).

• A power factor of 1 indicates that all the power is being used effectively, while a power factor of 0 means that no powe...read more