Electrical Machines A commutator with a diameter of 50 cm rotating at 1000 rpm. For a brush width of 1.5 cm, find the time of commutation in ms. 0.573. 0.512. 0.649. 0.443. 0.573. 0.512. 0.649. 0.443. 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 1.9 Ω 5.7 Ω 6 Ω 2.2 Ω 1.9 Ω 5.7 Ω 6 Ω 2.2 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the load current and flux of a DC motor are held constant and voltage applied across it armature is increased by 5%, the speed of the motor will Depends on other factor. Increase by 5%. Reduce by 5%. Remain unchanged. Depends on other factor. Increase by 5%. Reduce by 5%. Remain unchanged. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For which of the following loads, armature reaction is magnetizing in nature? pure capacitive load pure inductive load pure resistive load None of these pure capacitive load pure inductive load pure resistive load None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature of DC motor is laminated to reduce the mass. to reduce the inductor. to reduce the eddy current loss. to reduce the hysteresis loss. to reduce the mass. to reduce the inductor. to reduce the eddy current loss. to reduce the hysteresis loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following statement is true for an AC synchronous motor? It is a step angled motor. It is a high reluctance motor. It is a variable speed motor. It is a constant speed motor. It is a step angled motor. It is a high reluctance motor. It is a variable speed motor. It is a constant speed motor. ANSWER DOWNLOAD EXAMIANS APP