Electrical Engineering MCQ
Which of the following effects are associated with transmission lines
- Skin effect
- Ferranti effect
- Corona effect
- All of these
Correct answer: 4. All of these
Explanation:
- Skin Effect:
- The skin effect is a phenomenon associated with high-frequency alternating current (AC) in which the current tends to flow more on the surface of a conductor than through its interior.
- In transmission lines, especially at higher frequencies, the skin effect can cause an uneven distribution of current, leading to increased resistance and power losses.
- Ferranti Effect:
- The Ferranti effect is associated with long transmission lines and high-voltage alternating current systems. It refers to the voltage rise at the receiving end of a transmission line when the line is lightly loaded or unloaded.
- This effect occurs due to the capacitance between the conductors and the ground, causing the voltage at the receiving end to be higher than the voltage at the sending end.
- Corona Effect:
- The corona effect is the ionization of air surrounding a conductor carrying a high-voltage AC. This ionization can lead to the formation of a corona discharge, which is accompanied by a hissing or crackling noise, and sometimes visible light.
- In transmission lines, the corona effect can cause power loss, radio interference, and damage to the conductor due to the generation of ozone.
So, all of these effects—Skin Effect, Ferranti Effect, and Corona Effect—are associated with transmission lines, each influencing the behavior of the lines under different conditions.