Physics (Tricky)
posted by John on .
If the length of a conductor is doubled, the resistance will be ___ the original resistance.
A. less than  i think its A?
B. equal to
C. half
D. twice
A resistor most suited to dissipating high power levels would be:
A. Thick film resistor  i think it's A?
B. Wire wound resistor
C. Carbon resistor
D. Metal film resistor  i'm worried it might be D?

You are guessing, and hoping I will let you answer graze. You are wrong on both.

i'm stuck on these question for ages now, help!!

Think about resistance. If electrons want to get from one end of the conductor to the other, it would naturally seem likely that making the length greater would increase the resistance, since there's more material to penetrate.
Surely if you consult your class material, or even *gasp* google, you will come to see that resistance is directly proportional to the length, and inversely proportional to the crosssection area of the conductor.
So, doubling the length doubles the resistance. Doubling the diameter cuts the resistance by a factor of 4.
In about 1 minute on google I found
http://hyperphysics.phyastr.gsu.edu/hbase/electric/resis.html
which explains this.
Try it for the other question, and come back with what you found if you are still stuck. 
Thanks for all the answer, also now that you put it that way Steve, it makes a lot more sense ! thank you for your time !!

D.