What is corona ? Mention its positve effects .
Answer / rakesh
When an alternating potential difference is applied across
two conductors such that the spacing between the two is
large as comnpared to the spacing between the two , then an
electrostatic stress is set up , which gradually builds up
to make and makes the air around the conductor conducting ,
if he potential difference is increased to the extent that
exceeds the visual critical limit then comlete breakdown of
air takes place , and is accompanied by faint luminous glow
of violet colour , production of ozone gas , and hissing
noise .
DISADVANTAGES : 1. There is a definite los of power .
2. The corona current is non sinusoidal and hence causes
some disturbance to the neigbouring communication lines .
3. The ozone gas produced reacts with the conductor and
corrodes it .
ADVANTAGES : As the air becomes conducting so there is a
virtual increase in diameter of the conductor and henc
decreases the resistance.
2. It acts as a safety valve for neutralizing lightning
surges and overvoltages caused ddue to other transients .
Is This Answer Correct ? | 8 Yes | 1 No |
Q.1:What protection will be used on HT and LT side of 33/0.4 KV, MVA transformer. Indicate capacities of protective device to be used. Q.2:Which types of back-up protections are used in the power transformers? What do you understand by the term over travel in the relay? Q.3:How star and delta connected winding transformer are provided from earth fault
why need to be maintain power factor for industrial customer?
How can we calculate the power factor of an electrical appliance ? Is there any formula ? Is there any meter around to calculate it ? And how to use that meter ? thanks
what is the function of a commutator in a dc generator?
14 Answers College School Exams Tests, NTPC, TCS,
Why diversity factor are applied to the load?
what is the formula to find battery back up of ups?
in transformers for ex. 100mva and 400kv the secondary current is about 420 amps but for selection of bushing the capacity of selected bushing is 2000A why there is such big difference ?
What are RMU yard Safety Operating Procedures
why we increase the small speed of turbine when alternator just synchronized to grid in steam power plant
How to calculate meter constant in HT yard pls give me example for this issue
1 Answers Juniper Networks, MacLellan,
Why does the rotor rotate?
what is the difference between cable routing and scheduling?