Electrical Machines The mechanical power is developed by a DC motor is maximum when back emf is equal to half of applied voltage. none of above. back emf is equal to twice of applied voltage. back emf is equal to applied voltage. back emf is equal to half of applied voltage. none of above. back emf is equal to twice of applied voltage. back emf is equal to applied voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Hopkinson test is conducted under which of the following condition? no load half load any of the above full load no load half load any of the above full load ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole 50 Hz induction motor is running at 1470 rpm. What is the slip value? 0.2 0.02 0.4 0.04 0.2 0.02 0.4 0.04 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The stator frame in an induction motor is used to ventilate the armature. protect the whole machine. hold armature stamping in position. provide return path for the flux. ventilate the armature. protect the whole machine. hold armature stamping in position. provide return path for the flux. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The inertia constant H of a synchronous condenser is none of these. greater than that of turbo alternator. greater than that of hydro generator. equal to that of the effective length of the line. none of these. greater than that of turbo alternator. greater than that of hydro generator. equal to that of the effective length of the line. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V dc series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 Ω. The value of resistance which must be added to obtain rated torque at 1000 rpm is 2.2 Ω 1.9 Ω 5.7 Ω 6 Ω 2.2 Ω 1.9 Ω 5.7 Ω 6 Ω ANSWER DOWNLOAD EXAMIANS APP
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