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
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.
slip ring motor have high starting torque compare to squirrel cage motor and have good speed control also have high over loading capacity, smooth acceleration under heavy loads.
EXAMIANS