Synchronous Machines : EMF Polygon – 2

Which among the given harmonics are called belt harmonics?

For eliminating nth harmonic from the EMF generated in the phase of a 3-phase alternator, the chording angle should be

The chording angle for eliminating 5th harmonic should be __________

The winding’s for a 3-phase alternator are:
(i) 36 slots, 4 poles, span 1 to 8
(ii) 72 slots, 6 poles, span 1 to 10
(iii) 96 slots, 4 poles, span 1 to 21
The winding’s having pitch factor of more than 0.97 are

Consider the following statements:
(i) breadth factor for third harmonic k_d3 is more than that for fundamental k_d1
(ii) k_d3 < k_d1
(iii) k_d3 may be less or more than k_d1 depending upon the number of slots and poles
(iv) coil-span factor for third harmonic k_p3>k_p1 (coil span factor for fundamental)
(v) k_p3 < k_p1
(vi) k_p3 may be less or more than k_p1 depending upon the number of slots and poles

From these, the correct answer is

A 6-pole alternator with 36 slots carries a 2-phase distributed winding. Each coil is short pitched by one slot. The winding factor is given by

A 3-phase, 4-pole alternator has 48 stator slots carrying a 3-phase distributed winding. Each coil of the winding is short chorded by one slot pitch. The winding factor is given by ___________

In 48 slot, 4-pole,3 phase alternator, the coil-span is 10. Its distribution and pitch factors are respectively ___________

Machine A has 60° phase spread and machine B has 120° phase spread. Both the machines have uniformly distributed winding. The ratio of distribution factors of machine A to machine B is ___________