Electrical Machines which of the following type of brush and their application is/are correct copper graphite → low voltage high current density electro graphite → large ratings carbon brush → normal ratings All of these copper graphite → low voltage high current density electro graphite → large ratings carbon brush → normal ratings All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt generator builds up to a voltage of 220 V at no load while running at its rated speed. If the speed of the generator is raised by 25% kepping the circuit conditions unaltered, then the Voltage to which the machine would build up will increase to value lying between 220 V and 1.25 times 220 V increase to a value greater than 1.25 times 220 V increase to 1.25 times 220 V not change and remain at 220 V increase to value lying between 220 V and 1.25 times 220 V increase to a value greater than 1.25 times 220 V increase to 1.25 times 220 V not change and remain at 220 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole wave wound dc motor having flux per pole of 9.56 X 10-3 Wb contains 460 armature conductors. Calculate the back emf produced when it is running at a speed of 1500 rpm. 240 volt. 220 volt. 230 volt. 440 volt. 240 volt. 220 volt. 230 volt. 440 volt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Compensating windings are used in DC generators to neutralize the cross magnetizing effect of the armature reaction. mainly to reduce the eddy currents by providing local short circuit. None of these to provide path for the circulation of cooling air. to neutralize the cross magnetizing effect of the armature reaction. mainly to reduce the eddy currents by providing local short circuit. None of these to provide path for the circulation of cooling air. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The results of a slip test for determining direct axis (Xd) and quadrature axis (Xq) reactances of a star connected salient pole alternator are given below Phase values: Vmax = 108 V ; Vmin = 96 V Imax = 12 A ; Imin = 10 A Hence the two reactances will be Xd = 10.8Ω and Xq = 8Ω Xd = 8Ω and Xq = 10.8Ω Xd = 9.6Ω and Xq = 9Ω Xd = 9Ω and Xq = 9.6Ω Xd = 10.8Ω and Xq = 8Ω Xd = 8Ω and Xq = 10.8Ω Xd = 9.6Ω and Xq = 9Ω Xd = 9Ω and Xq = 9.6Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Rotor resistance speed control is used in dc shunt motor. slip ring induction motor. synchronous motor. squirrel cage induction motor. dc shunt motor. slip ring induction motor. synchronous motor. squirrel cage induction motor. ANSWER DOWNLOAD EXAMIANS APP