Question

Why is the length of the yoke made larger?

(a) to protect the armature windings

(b) to cover the armature windings

(c) to cover the field windings

(d) to cover and protect the field windings

The question was asked in examination.

My doubt stems from Frames of D.C. & A.C. Machines topic in section Aspects of Design of Mechanical Parts of Design of Electrical Machines

Answer 1

Right option is (d) to cover and protect the field windings

To elaborate: The length of the yoke is usually made larger than the pole cores. It is because to cover and protect the field windings.