Electrical Machines Considering a galvanometer is connected to the rotor of a 3 - Φ, 4 pole, 50 Hz IM and is making 130 oscillations in a minute, then calculate the rotor speed? 1450. 1435. 1500. 1440. 1450. 1435. 1500. 1440. 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 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 3.1 Ω 2 .1 Ω 1.8 9 Ω 1.79 Ω 3.1 Ω 2 .1 Ω 1.8 9 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Copper brushes in DC machine are used where high voltage and low current. None of these in both of above cases. where low voltage and high currents are involved. where high voltage and low current. None of these in both of above cases. where low voltage and high currents are involved. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC generator without commutator is a DC motor DC generator AC generator induction motor DC motor DC generator AC generator induction motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 2, 4 2, 3 1, 4 1, 3 2, 4 2, 3 1, 4 1, 3 ANSWER DOWNLOAD EXAMIANS APP
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