Question 421. 9.  A 400V, 15 kW, 4 pole, 50Hz, Y-connected induction motor has full load slip of 4%. The output torque of the machine at full load is

Question 422. 0.  For an induction motor, operating at a slip s, the ratio of gross power output to air gap power is equal to

Question 423. 1.  Under no load condition, if the applied voltage to an induction motor is reduced from the rated voltage to half the rated value,

Question 424. 4.  In a normal 3-phase slip-ring induction motor, the developed starting torque will

Question 425. 3. In a single phase induction motor driving a fan load, the reason for having a high resistance rotor is to achieve

Question 426. 2.  A three-phase cage induction motor is started by direct-on-line (DOL) switching at the rated voltage. If the starting current drawn is 6 times the full load current, and the full load slip is 4%, the ratio of the starting developed torque to the full load torque is approximately equal to

Question 427. 5.  A 3-phase induction machine operates on 3-phase fixed frequency ac mains at a per unit slip of 1.5. Consider the following statements regarding the operating condition of the machine 1. It drawn electrical power from the mains. 2. It draws mechanical power through the shaft. 3. It delivers electrical power to the mains. 4. It delivers mechanical power through the shaft. Of these statements :

Question 428. 6. The magnetising current component of the noload current of an induction motor is much larger than a corresponding transformer because of

Question 429. 8.  A 3-phase 4-pole slip-ring induction motor is supplied with appropriate voltage at 50 Hz to its stator and voltage at 10 Hz to its rotor through slip-rings. The phase sequence of both the voltages is same. The motor will produce steady torque at a sped of

Question 430. 9.  The rotor of a 4-pole 3-phase cage induction motor is replaced by a 3-phase, 4-pole wound rotor. When fed with normal supply, the machine will