Electrical Machines Which of the following alternators contain large number of poles? Aame in both alternators. Turbo alternators. Hydro alternators. None of these Aame in both alternators. Turbo alternators. Hydro alternators. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V, DC shunt motor is operating at a speed of 1440 rpm. The armature resistance is 1.0 Ω and armature current is 10 A. of the excitation of the machine is reduced by 10%, the extra resistance to be put in the armature circuit to maintain the same speed and torque will be 1.79 Ω 1.8 9 Ω 3.1 Ω 2 .1 Ω 1.79 Ω 1.8 9 Ω 3.1 Ω 2 .1 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the effect of armature reaction ? Both option B and C. None of the options. Armature flux distorts the main field flux. Armature flux weakens the main field flux. Both option B and C. None of the options. Armature flux distorts the main field flux. Armature flux weakens the main field flux. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following statement is correct, if short circuit ratio is high? High voltage regulation None of these Good voltage regulation Low short circuit current High voltage regulation None of these Good voltage regulation Low short circuit current ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer core is made up of a silicon steel laminations which has maximum flux density 1 Tesla. If it was cold rolled grain oriented its flux density increases to 1.6 Tesla. What is the saving in core size or area due to cold rolled grain oriented process? 68% 38% 40% 60% 68% 38% 40% 60% 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 ∝ φf E ∝ f/φ E ∝ φ/f E ∝ 1/(φf) E ∝ φf E ∝ f/φ E ∝ φ/f ANSWER DOWNLOAD EXAMIANS APP
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