Electrical Machines A 3-phase, 50 Hz, 4 pole induction motor is running at 1440 rpm. Find the rotor efficiency? 92% 96% 94% 95% 92% 96% 94% 95% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If peak value of phase mmf is F max , then peak value of the rotating field caused by three phase is (1/2)Fmax. Fmax. (3/2)Fmax. 3Fmax. (1/2)Fmax. Fmax. (3/2)Fmax. 3Fmax. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3 - Φ IM with line frequency f1 and winding factor kw1 and kw2 for stator and rotor respectively the ratio of per phase stator winding emf E1 to per phase rotor winding emf E2 at standstill is given by E1 / E2 = N1kw1 / N2kw2. E1 / E2 = f1kw1 / f2kw2. E1 / E2 = 1. E1 / E2 = N1 / N2. E1 / E2 = N1kw1 / N2kw2. E1 / E2 = f1kw1 / f2kw2. E1 / E2 = 1. E1 / E2 = N1 / N2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The principal of starting of 3 - Φ IM is similar to repulsion motor type starting. capacitor run IM. synchronous motor. transformer with short-circuited secondary. repulsion motor type starting. capacitor run IM. synchronous motor. transformer with short-circuited secondary. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In the V curve shown in figure below for a synchronous motor, the parameter of Y and X coordinates are, respectively Power factor and field current. Torque and field current. Armature current and field current. Armature current and torque. Power factor and field current. Torque and field current. Armature current and field current. Armature current and torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When a short circuit test on a transformer is performed at 25 V, 50 Hz, the drawn current is I1. If the test is performed by 25 V and 25 Hz and power drawn current is I2, then None of these I1 < I2 I1 > I2 I1 = I2 None of these I1 < I2 I1 > I2 I1 = I2 ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS