Electrical Machines The armature of DC machine is made of silicon steel lamination to reduce both eddy current and hysteresis loss. reduce hysteresis loss only. increase the permeability. reduce eddy current loss only. reduce both eddy current and hysteresis loss. reduce hysteresis loss only. increase the permeability. reduce eddy current loss only. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Exciting current of an induction motor is higher than power transformer. equal as power transformer. lesser than power transformer. none of these. higher than power transformer. equal as power transformer. lesser than power transformer. none of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A simple method of increasing the voltage of a DC generator is to increase the speed of shaft rotation. increase the source frequency. increase the number of turns in field coil. increase the number of turns in armature coil. increase the speed of shaft rotation. increase the source frequency. increase the number of turns in field coil. increase the number of turns in armature coil. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines which of the following type of brush and their application is/are correct All of these carbon brush → normal ratings electro graphite → large ratings copper graphite → low voltage high current density All of these carbon brush → normal ratings electro graphite → large ratings copper graphite → low voltage high current density ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of these types of motor is used in elevators? DC compound motor. None of these. DC shunt motor. DC series motor. DC compound motor. None of these. DC shunt motor. DC series motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The result of slip test on a 3-phase, 20 KVA, 400 V, 50 Hz connected salient pole alternator is given below- Phase value: Vmax = 100 V, Vmin = 96 V, Imax = 10 A and I min = 7 A. The direct and quadranature axis reactances are respectively 8.248 and 9.60 Ω. 14.28 and 5.54 Ω. 8.248 and 5.54 Ω. 14.28 and 9.60 Ω. 8.248 and 9.60 Ω. 14.28 and 5.54 Ω. 8.248 and 5.54 Ω. 14.28 and 9.60 Ω. ANSWER DOWNLOAD EXAMIANS APP