8.A. One characteristic of a typical universal motor is that it A. is usually designed for low-speed operation. B. has a low locked-rotor torque. C. operates at about the same speed on a-c and doc circuits.  8.B. A centrifugal starting switch in a split-phase motor operates on the principle that A. a high starting current opens the switch contacts. B. a higher speed changes the shape of a disk to open the switch contacts. C. the actuating weights move outward as the motor slows down.

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…

1. The rotor resistance and reactance per phase of a three-phase wound rotor induction motor are 0.035 and 0.15 ohm respectively. If an additional resistance is added, the starting torque is one half of maximum torque and the full load torque is three-fourth of the maximum. Determine the following: a. Full load speed b. speed at maximum torque c. value of additional resistance per required to achieve these conditions.