DGVCL Exam Paper (11-12-2011)
If the dielectric strength of the medium between the contacts builds up more rapidly than the restriking voltage the arc will
In all machine stator and rotor magnetic field rotates (stationary with respect to each other) at synchronous speed with respect to stationary observer.
Skin Effect: tendency of the current to crowd near the conductor surface.
Skin effect is proportional to frequency, conductor diameter and permiability. Skin effect increases effective resistance of conductor. In DC, no skin effect.
EXAMIANS