Electrical Machines If peak value of phase mmf is F max , then peak value of the rotating field caused by three phase is 3Fmax. (1/2)Fmax. Fmax. (3/2)Fmax. 3Fmax. (1/2)Fmax. Fmax. (3/2)Fmax. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In salient pole synchronous machine, if direct axis reactance and quadrature axis reactance is equal, then power developed due to reluctance is zero any of the above infinite value maximum zero any of the above infinite value maximum 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 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 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 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 1 X 1012 Ω - cm at 27°C and 0.1 X 1012 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the armature current of 5 Amp is flowing through the dc motor the torque produced is 47 Nm. Keeping the speed constant if the armature current is increased to 7 amp, calculate the new torque. Assume losses to be constant. 38.5 Nm. 27.73 Nm . 74 Nm. 65.8 Nm. 38.5 Nm. 27.73 Nm . 74 Nm. 65.8 Nm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately-excited dc motor has an armature resistance of 0.5 Ω. It runs off a 250 V dc supply Drawing an armature current of 20 A at 1500 rpm. The torque developed for an armature current Of 10 A, for the same field current, will be 15.92 Nm 16.55 Nm 15.28 Nm 15.6 Nm 15.92 Nm 16.55 Nm 15.28 Nm 15.6 Nm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 250 V DC generator in run at rated speed with no excitation. The open circuit voltage will be zero. 250 V. about 100 V. very small, say about 2 or 3 V. zero. 250 V. about 100 V. very small, say about 2 or 3 V. ANSWER DOWNLOAD EXAMIANS APP
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