PART A)
If we increase the voltage supply in an electromagnet then it will increase the current that is flowing in it
So here due to increase in current there will be increase in the magnetic field due to that electromagnet
PART B)
Here in electric generator the current is produced by rotating a coil between two strong magnets.
So here mechanical energy of rotation of coil is converted into electromagnetic energy.
PART C)
Step up transformer convert the lower voltage input into higher voltage output
here number of turns of coil in output side or secondary number of coils is more than the number of coils in primary side or input side
PART D)
Force on a moving charge is given by
here we know that
q = 0.000600 C
B = 4.21 T
now from above equation we have
direction of force is given by right hand thumb rule
using that rule we got force downwards