Electrical Machines A commutator with a diameter of 50 cm rotating at 1000 rpm. For a brush width of 1.5 cm, find the time of commutation in ms. 0.573. 0.443. 0.649. 0.512. 0.573. 0.443. 0.649. 0.512. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Under commutation results in sparking at the leading edge of the brush. no sparking. sparking the trailing edge of the brush. sparking at the middle of the brush. sparking at the leading edge of the brush. no sparking. sparking the trailing edge of the brush. sparking at the middle of the brush. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In an alternator, voltage drops occurs in armature resistance and leakage reactance. armature resistance, leakage reactance, armature reaction and earth connection. armature resistance only. armature resistance, leakage reactance and armature reaction. armature resistance and leakage reactance. armature resistance, leakage reactance, armature reaction and earth connection. armature resistance only. armature resistance, leakage reactance and armature reaction. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole dynamo with wave wound armature has 51 slots contains 20 conductors in each slot. If induced emf 357 Volts and speed is 8500 rpm, flux per pole will be 2.7 mWb. 1.2 mWb. 1.4 mWb. 3.5 mWb. 2.7 mWb. 1.2 mWb. 1.4 mWb. 3.5 mWb. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If two 8-pole dc machines of identical armature sare wound, one with lap winding and the other with wave winding, then lap-wound machine will have more rated voltage and more current wave-wound machine will have more rated current and more voltage wave-wound machine will have more rated voltage and less current lap-wound machine will have more rated voltage and less current lap-wound machine will have more rated voltage and more current wave-wound machine will have more rated current and more voltage wave-wound machine will have more rated voltage and less current lap-wound machine will have more rated voltage and less current ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The damper windings also called the squirrel cage windings or damper grids are provided in a synchronous motor to make it self starting. both (A) and (B). are provided on the stator for improving power factor. consists of short-circuited copper bars embedded in the field pole faces. are provided in a synchronous motor to make it self starting. both (A) and (B). are provided on the stator for improving power factor. consists of short-circuited copper bars embedded in the field pole faces. ANSWER DOWNLOAD EXAMIANS APP