Question

What is the relation between coil span and harmonics?

(a) low coil span decreases harmonics to less amount

(b) low coil span decreases the harmonics drastically

(c) high coil span decreases the harmonics drastically

(d) high coil span decreases the harmonics by small amount

I got this question during an interview.

Question is from Armature Design in division Design of Synchronous Machines of Design of Electrical Machines

Answer 1

The correct choice is (b) low coil span decreases the harmonics drastically

Easiest explanation: The coil span is kept low in order to decreases the harmonics. The advantage of having lower coil spans is that it reduces the harmonics drastically.