________________
the circuit of gap S is in resonance with R. The electromagnetic waves generated at S are then detected as sparks occurring across the gap R.
When a spark passes across S, stream of electrons pass across the spark gap from the negatively charged sphere to the positively charged sphere, reversing their polarities. In this situation the direction of the electric field at C and D will be reversed. Thus, at each passage of spark the polarity of charges on Q' and Q? reverses and the electric field direction in the surrounding region also reverses; i.e. the electric field oscillates. Further, the stream of electrons crossing the spark gap constitutes a current. This alternating current in the spark gap generates an alternating magnetic filed in the neighbourhood. Application of Ampere's right hand rule readily shows that the resulting magnetic field is perpendicular to the electric field. According to Maxwell S electromagnetic field theory, these electric and magnetic fields in the neighbourhood do not appear instantaneously. The influence of the oscillations of S spread to the neighbouring region with velocity of light. Thus, at various points in the region around S, the oscilla
tions have phases which depend upon their distance from S. (c) dd, 7979 , feuqur 54-55 8. dd, TYA 4T, fuqu 61 9. http:www.edntt,cin/articles reports/edmprocesses.html. by Dean Brink, Pesident
and Technical Director, EDM Technology Transfer. EDM: Principles of opera
tion, Part I, Different types of machining processes that use EDM. Pages 1, 2, 3 10. G.E.C. Type K Oil Circuit Breakers, by The General Electric Company of India
Ltd.
TOE HETI -778, 2004
-
81
Jain Education International
For Private & Personal Use Only
www.jainelibrary.org
