Electrical Machines In induction motor the 7th harmonic torque may make the motor rotate at (1 / 7)th synchronous speed. This is called cogging. resonance. harmonics. crawling. cogging. resonance. harmonics. crawling. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An induction motor has a rotor resistance of 0.002 Ω / phase. If the resistance is increased to 0.004 Ω / phase then the maximum torque will increase by 200% reduced to half increase by 100% remain unaltered increase by 200% reduced to half increase by 100% remain unaltered ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Find the number of poles required, when the frequency is 50Hz and speed of the motor is 500 rpm? 24 10 5 12 24 10 5 12 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of DC shunt motor if load is reduced The speed will increase in proportion to reduction in load. DC Shunt Motor The speed will increase abruptly. The speed will remains almost constant. The speed will increase in proportion to reduction in load. DC Shunt Motor The speed will increase abruptly. The speed will remains almost constant. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the full load speed of 3-phase, 50Hz induction motor is 950 rpm, what is its half load speed nearly equals to? 1000 rpm 975 rpm 940 rpm 950 rpm 1000 rpm 975 rpm 940 rpm 950 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The mmf produced by rotor currents of a 3 - Φ induction motor is at standstill with respect to stator mmf. rotates at slip speed with respect to stator mmf. rotates at the speed of rotor in the air gap. rotates at synchronous speed with respect to rotor. is at standstill with respect to stator mmf. rotates at slip speed with respect to stator mmf. rotates at the speed of rotor in the air gap. rotates at synchronous speed with respect to rotor. ANSWER DOWNLOAD EXAMIANS APP