Gujarat State Electricity Corporation Dispatch Executive Interview Questions and Answers

Losses in transformers can be categorized as copper losses and iron losses.

• Copper losses occur due to resistance in the windings and are also known as I^2R losses.

• Iron losses occur due to hysteresis and eddy currents in the core.

• Copper losses can be reduced by using larger conductors with lower resistance.

• Iron losses can be minimized by using high-quality magnetic materials and proper core design.

• Total losses in a tran...read more

Efficiency of a transformer is the ratio of output power to input power.

• Efficiency is affected by factors such as core losses, winding resistance, and load impedance.

• Efficiency can be improved by using high-quality materials and reducing losses.

• Efficiency is typically expressed as a percentage and can range from 50% to 99%.

• Efficiency is important in reducing energy waste and improving overall system performance.

Eddy current losses in transformers can be reduced by using laminated cores, increasing the core resistance, and minimizing the air gap.

• Use laminated cores to reduce eddy current losses

• Increase the core resistance by using high resistivity materials

• Minimize the air gap between the core and windings

• Use magnetic materials with low hysteresis losses

• Reduce the frequency of the alternating current

• Use thicker laminations to ...read more

High voltage is preferred for transmission of electrical power due to lower energy losses and reduced cost.

• High voltage reduces energy losses during transmission

• Reduced current flow at high voltage reduces the cost of transmission lines

• High voltage allows for longer transmission distances

• Step-up transformers increase voltage for transmission and step-down transformers decrease voltage for distribution

• Examples of high v...read more

Humming noise is generated due to the vibration of magnetic domains in a magnetic material.

• Magnetostriction is the property of magnetic materials to change their shape or dimensions when subjected to a magnetic field.

• This change in shape causes the magnetic domains to vibrate, which in turn generates a humming noise.

• The frequency of the humming noise is directly proportional to the frequency of the magnetic field.

• Magne...read more

Electrical circuits involve the flow of electric current, while magnetic circuits involve the flow of magnetic flux.

• Electrical circuits involve the use of conductors, insulators, and power sources to create a path for electric current to flow.

• Magnetic circuits involve the use of magnetic materials, such as iron, to create a path for magnetic flux to flow.

• Electrical circuits are used in a wide range of applications, inc...read more

Electrical appliances are devices that run on electricity to perform a specific task.

• Examples include refrigerators, washing machines, televisions, air conditioners, and vacuum cleaners.

• They are used in homes, offices, and industries for various purposes.

• They make our lives easier and more convenient.

• They require proper maintenance and care to ensure their longevity and safety.