NTT DATA, Inc. Junior Engineer Electrical Interview Questions and Answers

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

• Transformers are used to increase or decrease voltage levels in electrical circuits.

• They consist of two coils of wire, known as the primary and secondary coils, wrapped around a core.

• Step-up transformers increase voltage levels, while step-down transformers decrease voltage levels.

• Transformers are e...read more

The type of motor refers to the classification based on the design and operation of the motor.

• There are various types of motors such as DC motors, AC motors, synchronous motors, induction motors, etc.

• The type of motor is determined by factors like the power source, speed control, and construction.

• Each type of motor has its own advantages and applications in different industries.

• For example, DC motors are commonly used ...read more

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

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

• Primary coil receives electrical energy and creates a magnetic field

• Magnetic field induces a voltage in the secondary coil, transferring energy

• Used to step up or step down voltage in power distribution systems

• Examples include power t...read more

Types of transformers include step-up, step-down, isolation, autotransformer, and instrument transformer.

• Step-up transformer increases voltage

• Step-down transformer decreases voltage

• Isolation transformer provides electrical isolation between primary and secondary windings

• Autotransformer has a single winding with multiple taps

• Instrument transformer is used for measuring current or voltage in high voltage circuits

A current transformer is a type of instrument transformer that is used to measure alternating current.

• Current transformers step down current to a safe level for measurement or protection purposes.

• They have a primary winding connected in series with the circuit carrying the current to be measured.

• The secondary winding is connected to measuring or protective devices.

• Current transformers are commonly used in power systems...read more

Current transformer is used to measure current while potential transformer is used to measure voltage.

• Current transformer is connected in series with the circuit being measured, while potential transformer is connected in parallel.

• Current transformer steps down the current to a measurable level, while potential transformer steps down the voltage.

• Current transformer is used for protection and metering purposes, while po...read more

Current is the flow of electric charge in a circuit.

• Current is measured in Amperes (A).

• It is the rate of flow of electric charge past a point in a circuit.

• Current can be either direct current (DC) or alternating current (AC).

• In a series circuit, the current is the same at all points.

• In a parallel circuit, the total current is divided among the branches.

• Ohm's Law relates current, voltage, and resistance: I = V/R.

Voltage is the difference in electric potential between two points in a circuit, measured in volts.

• Voltage is the driving force that pushes electric current through a circuit

• It is measured in volts (V)

• Higher voltage means more potential energy available to move electrons

• Voltage can be DC (direct current) or AC (alternating current)

• Example: A battery provides a voltage of 1.5V to power a flashlight