Electrical Machines When a DC cummulative compound wound motor is loaded Torque and speed both increase. Both torque and speed decrease. Torque decrease and speed increases. Torque increase and speed decrease. Torque and speed both increase. Both torque and speed decrease. Torque decrease and speed increases. Torque increase and speed decrease. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the necessity of copper brushes in a dc motors? To increase the flux cutting by the rotor. None of these. To absorb the mechanical shocks produced during running condition. To convert alternating supply current to direct current. To increase the flux cutting by the rotor. None of these. To absorb the mechanical shocks produced during running condition. To convert alternating supply current to direct current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a dc machine, 1. physically, the brush axis is along the direct axis 2. physically, the brush axis is along the interpolar axis 3. schematically, the brush axis is along the direct axis 4. schematically, the brush axis is along the quadrature axis 5. armaturemmf is directed along the brush axis From these, the correct statements are 1, 4,5 2, 4, 5 2, 3, 5 1 , 3, 5 1, 4,5 2, 4, 5 2, 3, 5 1 , 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In which of the following motors DC excitation is not required? hysteresis motor 3-phase synchronous generator 3-phase synchronous motor reluctance motor hysteresis motor 3-phase synchronous generator 3-phase synchronous motor reluctance motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the handle of a three point starter goes to back to OFF position, it may be due to high filed circuit resistance. over load. zero or very low voltage supply. all of these. high filed circuit resistance. over load. zero or very low voltage supply. all of these. 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 ∝ f/φ E ∝ φ/f E ∝ φf E ∝ 1/(φf) E ∝ f/φ E ∝ φ/f E ∝ φf E ∝ 1/(φf) ANSWER DOWNLOAD EXAMIANS APP
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