Electrical Machines The fall in speed of the DC generator due to increase in load can be corrected by increasing the input to the prime mover. cooling the armature. increasing the excitation. reducing the load voltage. increasing the input to the prime mover. cooling the armature. increasing the excitation. reducing the load voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Addition of 0.3 % to 4.5 % silicon to iron None of these reduces the saturation magnetization. increases the electrical resistivity of iron. increases the hysteresis loss. None of these reduces the saturation magnetization. increases the electrical resistivity of iron. increases the hysteresis loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The mmf produced by rotor currents of a 3 - Φ induction motor rotates at synchronous speed with respect to rotor. rotates at the speed of rotor in the air gap. is at standstill with respect to stator mmf. rotates at slip speed with respect to stator mmf. rotates at synchronous speed with respect to rotor. rotates at the speed of rotor in the air gap. is at standstill with respect to stator mmf. rotates at slip speed with respect to stator mmf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of rotating magnetic field of 8 pole 50 Hz induction motor is 1500 rpm 3000 rpm 1000 rpm 750 rpm 1500 rpm 3000 rpm 1000 rpm 750 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is power factor of a 3 - φ induction motor at no load? Low. Same as full load. High. Equal to 1. Low. Same as full load. High. Equal to 1. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : 1. interpole windings are connected in series with armature windings 2. polarity of interpoles must be the same as that of the main poles in advance 3. distortion of the main field under the pole shoes is not affected by the use of interpoles From above, the correct answer is 1 alone 1 and 3 2 and 3 1 and 2 1 alone 1 and 3 2 and 3 1 and 2 ANSWER DOWNLOAD EXAMIANS APP