Induction

can you please help me with this multiple choice homeowrk question asap

Q2] Fill in the blank (9 Marks) 1-The current drwan by the armature of D.C. motor is directly proportional to 2- The speed of a D.C. shunt-wound motor will shunt field regulator is increased. 3- The synchronous speed of a three-phase induction motor is number of pairs of poles. Rotor copper losses Rotor input power in induction motor = 5- A 4-pole three-phase induction motor has a synchronous speed of 25 r.p.s. The frequency of the supply to the stator is_ Hz. 6- The power input to a mains transformer is 200VA. If the primary current is 2.5A, the secondary voltage is 2V and assuming no losses in the transformer, the turns ratio step down. is 7- A 200kVA transformer has an iron loss of 1 kW and full load cu loss of 2 kW. Its load kVA corresponding to maximum efficiency is kVA. 8- If cu loss of a transformer at 7/8th full load is 4900 W, then its full-load cu loss would be watt. 4- if the value of resistance of the proportional to the 9- The slight curvature at the lower end of the open…

18. What is the frequency on the rotor of a 3-phase squirrel-cage induction motor, when the rotor is at a standstill with the stator excited? a) equal to stator frequency b) equal to stator frequency times percent slip c) equal to zero d) none of the above

A three – phase 400 V, 50 Hz induction motor has a speed of 900 rpm on full – load. The motor has six poles. How many complete alternations will the rotor voltage takes per minute? (a). 30                          (b). 60 (c). 300                        (d). 600

6. Explain the following concepts: a. Explain how a rotating magnetic field is produced in a three-phase induction motor. b. Explain the rotor action on a three-phase squirrel cage motor when the load increases from NO-LOAD to rated FULL- LOAD