The "back emf" of a motor refers to a source of voltage that
a. occurs when the motor runs backwards.
b. occurs when the motor is used as a generator.
c. is biggest when the current through the motor is biggest.
d. is biggest when the motor turns fastest.
d
You might also like to view...
The most active galactic nuclei are usually found at large distances from us; relatively few nearby galaxies have active galactic nuclei. What does this imply?
A) Supermassive black holes existed only when the universe was young and no longer exist today. B) Active galactic nuclei tend to become less active as they age. C) Active galactic nuclei can form only at large distances from the Milky Way. D) The jets seen in many active galactic nuclei must cause them to move far away from us.
Two vectors lying in the xy plane are given by the equations 
and 
. The value of 
class="Wirisformula" align="middle" /> is A.
B.
C.
D.
E.
Eras are divided first into smaller time units called ______________
Fill in the blank(s) with correct word
All continental landmasses joined together as Pangaea resulted in
A) a reduction in shallow marine habitats. B) a long duration of high sea level. C) an increase of seafloor spreading. D) increased species diversification.