Electrical Machines A 3 - Φ induction motor draws an current of 50 A from mains when starts by direct switching. If an auto transformer with 60 % tapping is used for starting the current drawn from the mains will be 80. 36. 50. 18. 80. 36. 50. 18. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of a DC Shunt motor if the load is decreased to some extent, what will happen to its speed? The speed will increase abruptly. The speed will increase gradually. The speed will remains almost constant. The speed will increase in proportion to reduction in load. The speed will increase abruptly. The speed will increase gradually. The speed will remains almost constant. The speed will increase in proportion to reduction in load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt generator builds up 230 V when driven in clockwise direction. In case it is driven in anti clockwise direction, other things remaining unchanged, then the voltage build up is not possible some what less than 230 V some what more than 230 V 230 V not possible some what less than 230 V some what more than 230 V 230 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the armature current of 5 Amp is flowing through the dc motor the torque produced is 47 Nm. Keeping the speed constant if the armature current is increased to 7 amp, calculate the new torque. Assume losses to be constant. 38.5 Nm. 65.8 Nm. 27.73 Nm . 74 Nm. 38.5 Nm. 65.8 Nm. 27.73 Nm . 74 Nm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in DC generators will result in short circuit. open circuit. reduction in generated emf. increase in slip. short circuit. open circuit. reduction in generated emf. increase in slip. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To control the speed of an induction motor, the supply frequency is reduced by 10%. For the same magnetizing current to remain constant, the supply voltage must be reduced by 10% reduced by 20% increased by 20% increased by 10% reduced by 10% reduced by 20% increased by 20% increased by 10% ANSWER DOWNLOAD EXAMIANS APP