Electrical Machines A transformer has hysteresis loss of 30 W, at 240 V, 60 Hz. The hysteresis loss at 200 V, 50 Hz will be 36 W. 30 W. 25 W. 28 W. 36 W. 30 W. 25 W. 28 W. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For small value armature current Ia the torque developed by a DC series motor is proportional to Ia. √Ia. Ia2. 1/Ia. Ia. √Ia. Ia2. 1/Ia. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Unbalanced supply voltage given to a 3 - φ, delta connected induction motor will cause less heating of the rotor. less heating of the rotor. negative sequence current. all of these. less heating of the rotor. less heating of the rotor. negative sequence current. all of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of induction motors the ratio of length to pole pitch for minimum cost, is taken as 3 to 5. 2 to 3. 1.5 to 2. 1.0. 3 to 5. 2 to 3. 1.5 to 2. 1.0. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is not a necessary condition to be satisfied for synchronising an incoming alternator to an already operating alternator? same prime mover speed same voltage magnitude same frequency same phase sequence same prime mover speed same voltage magnitude same frequency same phase sequence ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines φA DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 960 RPM 940 RPM 970 RPM 920 RPM 960 RPM 940 RPM 970 RPM 920 RPM ANSWER DOWNLOAD EXAMIANS APP
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