Electrical Machines A shunt generator has a critical field resistance of 300 Ω at a speed of 800 rpm if the speed is raised to 1000 rpm the critical field resistance is 225 Ω. 150 Ω. 375 Ω. 145 Ω. 225 Ω. 150 Ω. 375 Ω. 145 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A single phase transformer has specifications as 250 KVA, 11000 V/415 V, 50 Hz. What are the values of primary and secondary currents? primary = 22.7 A, secondary = 602.4 A primary = 11.4 A, secondary = 301 A primary = 301 A, secondary = 22.7 A primary = 602 A, secondary = 22.7 A primary = 22.7 A, secondary = 602.4 A primary = 11.4 A, secondary = 301 A primary = 301 A, secondary = 22.7 A primary = 602 A, secondary = 22.7 A ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the mechanical power is developed by a DC motor maximum Back emf is equal to half of applied voltage. Back emf is equal. back emf is equal to applied voltage. None of above. Back emf is equal to half of applied voltage. Back emf is equal. back emf is equal to applied voltage. None of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a three phase star - delta transformer, what is the angle difference between primary and secondary phase voltages? Delta side lags by -30°. Star side leads by 30°. Star side lags by -30°. Delta side leads by 30°. Delta side lags by -30°. Star side leads by 30°. Star side lags by -30°. Delta side leads by 30°. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous machine, if φ is the flux per pole and f is the frequency of the emf induced E then E ∝ 1/(φf) E ∝ φ/f E ∝ φf E ∝ f/φ E ∝ 1/(φf) E ∝ φ/f E ∝ φf E ∝ f/φ ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Unbalanced supply voltage given to a 3 - φ, delta connected induction motor will cause negative sequence current. less heating of the rotor. less heating of the rotor. all of these. negative sequence current. less heating of the rotor. less heating of the rotor. all of these. ANSWER DOWNLOAD EXAMIANS APP