Question

The generated e.m.f from 4-pole armature having 1 conductors driven at 1 rev/sec having flux per pole as 10 Wb, with wave winding is ___________

(a) 30 V

(b) 40 V

(c) 70 V

(d) 20 V

The question was posed to me in class test.

My doubt is from Induction Motors topic in portion Speed Control of Direct Current Motors & Induction Motors of Electric Drives

Answer 1

Right answer is (d) 20 V

To explain: The generated e.m.f can be calculated using the formula Eb = Φ×Z×N×P÷60×A, Φ represent flux per pole, Z represents the total number of conductors, P represents the number of poles, A represents the number of parallel paths, N represents speed in rpm. In wave winding number of parallel paths are 2. Eb = 10×4×1×60÷60×2 = 20 V.