I have a test tomorrow and I had a few questions on the review! Please help 
You don’t have to answer all….but it would be appreciated 
*Which of the following is the reason "soft" iron is used for the cores of electromagnets?
a. difficult to magnetize
b. easily magnetized
c. has no magnetic domains
d. permanent magnet
*In an electric motor, periodically changing the direction of current in the electromagnet can cause the axle to spin because
a. electromagnet loses magnetism
b. mechanical energy is converted to electric energy
c. moving electrons push the electromagnet in opposite direction
d. magnetic field reverses direction
* How can the voltage in a coil of wire be increased in the process of electromagnetic induction?
a. move magnet inside the coil of wire more slowly.
b. hold magnet stationary
c. move coil of wire slowly, and keep magnet stationary
d. move magnet inside the coil of wire more rapidly
* The process of generating an electric current by moving an electrical conductor relative to a magnetic field is called:
a. magnetization
b. electromagnetic force
c. electromagnetic induction
d. alternating current
* How are fossil fuels used to generate electrical energy?
a. heat from burning fuel spins magnets inside an electrical motor
b. heat from burning fuel creates steam that spins a turbine
c. heat from burning fuel causes an electric motor to produce a current
d. heat from burning fuel creates steam that turns a transformer
Thanks so much!! Again, you don’t have to answer all…and these are only the one’s i didn’t understand! Please help