JNTU B.Tech II Semester Examinations, HIGH VOLTAGE ENGINEERING, Apr/May 2008
(Electrical & Electronic Engineering)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
1. Discuss about surge voltage and their distribution and control in high voltage power
2. (a) Explain in detail ionization by collision with neat diagrams.
(b) Explain the difference between photo-ionization and photo electric emission. [8+8]
3. Explain thermal breakdown in solid dielectrics. How this mechanism is more significant than the other mechanisms. 
4. (a) Explain with diagrams, different types of rectifier circuits for producing high DC voltages.
(b) Determine the ripple voltage and regulation of a 10 stage Cockroft-Walton type DC voltage Multiplier circuit having a stage capacitance = 0.01 ?F, supply voltage = 100 kV at a frequency of 400 Hz and load Current = 10 mA.
5. What are the problems associated with measuring very high impulse voltages?
Explain how these can be taken care during measurments. 
6. (a) Explain the different theories of charge formation in clouds?
(b) What are the mechanisms by which lightning strokes develop and induce over
voltages on overhead power lines? [8+8]
7. Explain the concept of apparent charge in partial discharge measurements. Describe
a simple experiment technique to measure partial discharge 
8. Mention the different electrical tests done on isolators and circuits breakers.