Question

a) The input current to a 220 V, short-shunt compound motor at no load is 6 A. The shunt- field circuit resistance is 220 Ω; the armature resistance is 0.112, and the series-field resistance is 0.1 Ω, what is the stray power loss ? (b) Assume the input rating of the motor in Part (a) to be 66 A at 220 V with a no-load speed of 1000 rpm. If the stray power loss varies as the counter-electromotive force and the effects of armature reaction are considered negligible. Determine the efficiency at rated input. Exercise :2. (6Marks) A differential compound motor has a varying load upon it which requires a variation in armature current from 60 A to120 A. if te senes-field current causes the air-gap flux to change by 2 percent for each 10 A of armature current, a) What is the difference between Cjmulative and differential compound motor b) Find the ratio of torques developed for the two values of armature current. Exercise :3. &Marks) A long-shunt compound generator has armature, shunt field and series field resistances of (Ras 0.4 Ω , Rsh #131 Ω . and Rse-o.3 Ω ) respectively. When supplying a load of 10 kw at a terminal voltage of 250 V the input power supplied by the driving motor is 12.4 kw. Calculate (a) the generated emf, (b) the efficiency, (c) the iron, friction and windage loss, and (d) the total fixed losses. good vck Dr Loman

Answer 1

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As per HOMEWORKLIB POLICY I needed to answer only first question completely which I have done, as you have posted multiple questions.Feel free to ask if you have any query.Thank you.