Electrical Machines Minimum allowable resistivity of power transformer insulating oil is generally taken as 2 X 1012 Ω - cm at 27°C and 0.2 X 1012 1 X 1012 Ω - cm at 27°C and 0.1 X 1012 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 4 X 1012 Ω - cm at 27°C and 0.4 X 1012 2 X 1012 Ω - cm at 27°C and 0.2 X 1012 1 X 1012 Ω - cm at 27°C and 0.1 X 1012 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 4 X 1012 Ω - cm at 27°C and 0.4 X 1012 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Larger values of air flux density is taken while designing IM for larger output. both. none. larger bore diameter. larger output. both. none. larger bore diameter. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a DC Shunt Motor having armature resistance of 0.5 Ω and 2A armature current at no-load, when the armature current is changed to 20A at loaded condition the speed is 1000 r.p.m. What is the speed at no-load? 963.8 r.p.m. 4575.4 r.p.m. 1130 r.p.m. 1037.5 r.p.m. 963.8 r.p.m. 4575.4 r.p.m. 1130 r.p.m. 1037.5 r.p.m. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3-phase induction motor, torque and supply voltage are related as T ∝ 1/V² T ∝ V T ∝ 1/V T∝ V² T ∝ 1/V² T ∝ V T ∝ 1/V T∝ V² ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole, 3-phase induction motor is running at 4% slip at full load. If the speed of the motor is 720 rpm, the supply frequency is 60 Hz 40 HZ 50 Hz 25 Hz 60 Hz 40 HZ 50 Hz 25 Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed regulation of a DC motor is given as (NfL − NnL)/NnL. NnL − NfL. (NnL − NfL)/NfL. NnL/NfL. (NfL − NnL)/NnL. NnL − NfL. (NnL − NfL)/NfL. NnL/NfL. ANSWER DOWNLOAD EXAMIANS APP