Electrical Machines What is the necessity of copper brushes in a dc motors? 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. To convert alternating supply current to direct current. To absorb the mechanical shocks produced during running condition. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Short circuiting is caused in the armature winding due to failure of insulation between two commutator bars. failure of insulation between two turns of coil. any of above. grounding of two or more turns of the same coil. failure of insulation between two commutator bars. failure of insulation between two turns of coil. any of above. grounding of two or more turns of the same coil. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two dc machines A and B, using the same conductor material, have armature circuit resistances of 0.4 Ω and 1.2 Ω respectively. Of the two machines, A is bigger than B for the same voltage rating both are of the same size for the same current rating A is bigger than B for the same current rating B is bigger than A for the same current rating A is bigger than B for the same voltage rating both are of the same size for the same current rating A is bigger than B for the same current rating B is bigger than A for the same current rating ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Skewing of cage rotors offers the following advantages less noise. locking tendency is reduced. all of below. uniform torque. less noise. locking tendency is reduced. all of below. uniform torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the air gap of IM is increased, ____________ will increase. magnetizing current. air gap flux. speed. power factor. magnetizing current. air gap flux. speed. power factor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In speed control of DC shunt motor by varying field flux, what may be the value of field regulator? 10 ohm 0.2 ohm 2 ohm. 100 ohm 10 ohm 0.2 ohm 2 ohm. 100 ohm ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS