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. cheaper in cost. lighter in weight. easy to cast owing to its low melting point and is easily available. of low resistivity. cheaper in cost. lighter in weight. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor has which of the following characteristics? Has a poor torque. Has its field winding consinting of thick wire and less no of turns. Can be started easily without load. Has a almost constant speed. Has a poor torque. Has its field winding consinting of thick wire and less no of turns. Can be started easily without load. Has a almost constant speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The heat transfer by convection in a transformer least depends on temperature difference. air velocity. color of the paint. surface area. temperature difference. air velocity. color of the paint. surface area. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ, 6 pole, 50 Hz IM has a rotor speed of 987 rpm find rotor frequency? 0.65 Hz. 0.70 Hz. 0.75 Hz. 60 Hz. 0.65 Hz. 0.70 Hz. 0.75 Hz. 60 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An induction motor has a rotor resistance of 0.002 Ω / phase. If the resistance is increased to 0.004 Ω / phase then the maximum torque will increase by 100% increase by 200% remain unaltered reduced to half increase by 100% increase by 200% remain unaltered reduced to half ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Minimum allowable resistivity of power transformer insulating oil is generally taken as 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 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 ANSWER DOWNLOAD EXAMIANS APP