Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
Corona is accompanied by
Violet visible discharge in darkness
Hissing sound
Vibration
All of above
All of above
Corona is an electrical discharge brought on by the ionization of a fluid such as air surrounding a conductor that is electrically charged. When the potential gradient exceeds the dielectric strength of air, the surrounding air breaks down, resulting in a luminous glow, audible hissing, and mechanical vibrations.
Corona is an electrical discharge brought on by the ionization of a fluid such as air surrounding a conductor that is electrically charged. When the potential gradient exceeds the dielectric strength of air, the surrounding air breaks down, resulting in a luminous glow, audible hissing, and mechanical vibrations.
VcтАЛ=m0тАЛg0тАЛ╬┤rln(rDтАЛ) тАФ disruptive critical voltage equation
PcтАЛ=╬┤242тАЛ(f+25)DrтАЛтАЛ(VтИТVcтАЛ)2├Ч10тИТ5 тАФ power loss due to corona
The phenomenon occurs due to the non-uniform electric field around circular conductors. When the operating voltage exceeds the disruptive critical voltage (VcтАЛ), air molecules near the conductor surface ionize. This creates charged particles that accelerate, leading to further ionization (Townsend discharge) and the characteristic manifestations listed.
Corona is more prevalent in AC systems than DC systems.
It causes power loss and can interfere with radio communication due to harmonic generation.
Rough and dirty conductors increase the likelihood of corona discharge.
The presence of ozone gas is a chemical side effect of corona.
Acts as a natural lightning arrester for overhead lines by dissipating some energy
Results in significant power loss
Causes electromagnetic interference (EMI) with communication lines
Leads to the formation of ozone gas, which is corrosive to the conductor material
Visible discharge appears as a faint violet light.
Hissing sound is produced due to the oscillatory motion of air ions.
Vibration is caused by the electrostatic repulsion between the ionized air and the conductor surface.
D is correct тАФ Corona discharge manifests physically through light emission, acoustic noise, and mechanical oscillations.
Always remember that corona loss is directly proportional to (f+25), meaning higher frequency systems (like those in aircraft or high-frequency drives) suffer significantly more corona losses than standard 50Hz/60Hz grid power.