Power Grid Corporation of India Trainee Interview Questions and Answers

Parameters of transmission line include resistance, inductance, capacitance, and conductance.

• Resistance: opposition to the flow of current

• Inductance: ability to store energy in a magnetic field

• Capacitance: ability to store energy in an electric field

• Conductance: ability to conduct electric current

• Examples: coaxial cable, waveguide, twisted pair cable

Hysteresis curve is a graphical representation of the relationship between magnetic field strength and magnetization of a material.

• It shows the lag between the magnetic field and the magnetization of a material.

• It is used to study the magnetic properties of materials.

• It is commonly used in the design of magnetic circuits and devices.

• Examples include transformer cores, magnetic storage devices, and electric motors.

• The s...read more

We use step-up transformers to reduce power loss during transmission by increasing voltage and decreasing current.

• Step-up transformers increase voltage and decrease current, which reduces power loss during transmission.

• This is because power loss is proportional to the square of the current, so reducing current reduces power loss.

• For example, power is transmitted over long distances at high voltages (e.g. 500 kV) to red...read more

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

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

• It ranges from 0 to 1, with 1 being the most efficient.

• A low power factor can result in higher energy costs and equipment damage.

• Capacitors can be used to improve power factor.

• Power factor is important in industries where large amounts of electrical power are used.