Electrical Machines A 240 V dc series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 Ω. The value of resistance which must be added to obtain rated torque at 1000 rpm is 5.7 Ω 2.2 Ω 1.9 Ω 6 Ω 5.7 Ω 2.2 Ω 1.9 Ω 6 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Direct-on-line (DOL) starters are not suitable for starting large DC motors, because the starting torque becomes low. the motor may run away. the starting current will be enormously high. the motor may not start. the starting torque becomes low. the motor may run away. the starting current will be enormously high. the motor may not start. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In 3 - Φ induction motor some times copper bars are placed deep in the rotor to improve power factor. reduce copper loss. improve efficiency. improve starting torque. improve power factor. reduce copper loss. improve efficiency. improve starting torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer has hysteresis loss of 30 W, at 240 V, 60 Hz. The hysteresis loss at 200 V, 50 Hz will be 36 W. 30 W. 28 W. 25 W. 36 W. 30 W. 28 W. 25 W. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If we increase the rotor reactance value, the maximum torque will decrease not changed None of these increase decrease not changed None of these increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The field divertor resistance for a DC series motor is of order of 10 Ω 50 Ω 0.1 Ω 100 Ω 10 Ω 50 Ω 0.1 Ω 100 Ω ANSWER DOWNLOAD EXAMIANS APP
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