Why do motors have gaps or breaks throughout the rotor and commutator? a) It makes the motor cheaper since not as much material is needed.
b) Only some sections of the rotor will act as electromagnets, causing the rotor too always be pushed in the same direction.
c) It allows some of the magnetic field to escape so that rotor doesn't get too stressed.
d) It lets air into the motor to keep it cool since the electricity can make it hot.
e) It happens when rotors don't use enough oil, so they crack.

Its the second option

Explanation:

I have the same text and everything I had did it yesterday and picked the second one and it was right so yea. Hopefully that helps. Is this fro STEM physics

an obstruction

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.