essays

Question 1

magnet option:
1. domain?
2. magnetic materials?
3. why do they work?
4. what makes a magnet?

Answer 1

1. a group of aligned atoms having a single magnetic field (magnetic fields of individual ions cause other atoms to align with it; once a certain number is aligned it becomes a domain)
2. see below
   a. diamagnetic: 0 unpaired and repel
   b. paramagnetic: 1 unpaired and attract
   c. ferromagnetic: 2 or more unpaired and attract
3. the magnetic fields that surround them have an attractive force that is caused mostly by electron spin
4. materials that are attracted to other magnets may become magnets if they are magnetically hard

Question 2

electric motors vs generators
compare & contrast

Answer 2

COMPARE:
1. electric motors convert electricity to motion; and generators convert motion to electricity - both deal with electricity and motion
2. both can be DC or AC
3. for AC, both use slip rings and for DC, both use a commutator
4. generators and electric motors both have an armature
5. they are almost identical, but both of them only will act as either a generator or electric motor instead of switching because it is more efficient

CONTRAST:
1. electric motors go from electricity to motion; generators are opposite
2. electric motors are more common for things that move in a circular rotation; generators move in a loop that is not typically very round
3. generators also can be MHD generators
4. generators made the production of electricity practical