# Skyler MacDougall

## Homework 14: due 4/20/2020

9. A separate excited DC generator turning at 1400r/min produces an induced voltage of 127V. The armature resistance is $2\Omega$ and the machine delivers a current of 12A. Calculate the terminal voltage.



10. A separately excited DC generator produces a no-load voltage of 115V. What happens if:
    1. the speed is increased by 20%?
    2. the direction of rotation is reversed?
    3. the exciting current is increased by 10%?
    4. the polarity of the field is reversed?



22. A 200W, 120V, 1800r/min DC generator has 75 communtator bars. The brush width is such as to cover 3 commutator segments. Show the duration of the commutation process is equal to 1.33ms.