Where is the density of the material greater, at point B or point C?
Explain why.

The density is greater at point C

Explanation: At that point

The convention current slowly cools off

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.

the amount of current in the coil