Electrical Machines The starting resistance of DC motor is generally 1000 ohms. Infinitely large. around 500 ohms. Low. 1000 ohms. Infinitely large. around 500 ohms. Low. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Induction motors normally use cast aluminium rotor because aluminium is easy to cast owing to its low melting point and is easily available. of low resistivity. lighter in weight. cheaper in cost. easy to cast owing to its low melting point and is easily available. of low resistivity. lighter in weight. cheaper in cost. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Minimum allowable resistivity of power transformer insulating oil is generally taken as 1 X 1012 Ω - cm at 27°C and 0.1 X 1012 2 X 1012 Ω - cm at 27°C and 0.2 X 1012 4 X 1012 Ω - cm at 27°C and 0.4 X 1012 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 1 X 1012 Ω - cm at 27°C and 0.1 X 1012 2 X 1012 Ω - cm at 27°C and 0.2 X 1012 4 X 1012 Ω - cm at 27°C and 0.4 X 1012 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be 59.2%. 57.1%. 48.0%. 88.8%. 59.2%. 57.1%. 48.0%. 88.8%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator in case the brushes are moved so as to bring them in magnetic neutral axis, then, there will be cross-magnetization as well as demagnetization. none of above. demagnetisation. cross-magnetisation. cross-magnetization as well as demagnetization. none of above. demagnetisation. cross-magnetisation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Satisfactory commutation of DC machine requires brushes should smoothly run in the holders. brushes should be of proper grade and size. All of these smooth, concentric commutator properly undercut. brushes should smoothly run in the holders. brushes should be of proper grade and size. All of these smooth, concentric commutator properly undercut. ANSWER DOWNLOAD EXAMIANS APP
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