Question

How is the mmf required at full load obtained for the calculation of height of poles?

(a) using closed circuit characteristics

(b) using open circuit characteristics

(c) using formula

(d) using equivalent circuit

This question was posed to me in exam.

My doubt stems from Pole Design topic in portion Thermal Design Aspects of Electrical Machines & D.C of Design of Electrical Machines

Answer 1

Right option is (b) using open circuit characteristics

To explain: The mmf at full load is calculated using the magnetization curve. The open circuit characteristics are obtained which help in finding out the mmf at full load.