reversing the armature terminal is better & applied in

practice.this is becoz of the following drawbacks in field

reversing method.

* high voltage build-up during reversing the field terminal

which is high enough to puncture the insulation of field

coil.

* high flash-over will occur.

* during reversal, the armature current should be limited

to the rated value,otherwise it will draw twice the time of

starting current.we can insert the external resistance to

limit the current while reversing the armature

terminal.whereas,in field reversal we cannot give any

provision to limit armature over current.