Electrical Machines The starting resistance of DC motor is generally around 500 ohms. Low. Infinitely large. 1000 ohms. around 500 ohms. Low. Infinitely large. 1000 ohms. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The brushes of a DC machine should be placed on the armature in the polar axis. commutator in the polar axis. commutator in the inter polar axis. armature midway between poles. armature in the polar axis. commutator in the polar axis. commutator in the inter polar axis. armature midway between poles. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the necessity of copper brushes in a dc motors? To convert alternating supply current to direct current. To absorb the mechanical shocks produced during running condition. None of these. To increase the flux cutting by the rotor. To convert alternating supply current to direct current. To absorb the mechanical shocks produced during running condition. None of these. To increase the flux cutting by the rotor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3 - Φ IM with line frequency f1 and winding factor kw1 and kw2 for stator and rotor respectively the ratio of per phase stator winding emf E1 to per phase rotor winding emf E2 at standstill is given by E1 / E2 = f1kw1 / f2kw2. E1 / E2 = N1kw1 / N2kw2. E1 / E2 = 1. E1 / E2 = N1 / N2. E1 / E2 = f1kw1 / f2kw2. E1 / E2 = N1kw1 / N2kw2. E1 / E2 = 1. E1 / E2 = N1 / N2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the back emf in DC motor vanishes suddenly the motor will run at very low speed. burn. start haunting. run at very high speed. run at very low speed. burn. start haunting. run at very high speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the frequency of input voltage of a transformer is increased keeping the magnitude of voltage unchanged, then both hysteresis loss(Ph) and eddy current loss(Pe) will increase Ph will decrease but Pe will remain same Pe will increase but Ph will decrease Ph will increase but Pe will decrease both hysteresis loss(Ph) and eddy current loss(Pe) will increase Ph will decrease but Pe will remain same Pe will increase but Ph will decrease Ph will increase but Pe will decrease ANSWER DOWNLOAD EXAMIANS APP
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