Could do with some help PlZ

[cm304eex]

Hi all I have no idea where to start with this question so any help would be more than welcome:O

A certain grade of resistance wire has a resistivity of 50 * 10-6 ohm mtr. Find the length of wire needed to make a heating element of resistance 54ohm. Assume the cross sectional area of the wire is 0.4mm Sq.

 

[ianmacd]

So....

p=RA/l

where

p is the static resistivity (measured in ohmm)

R is the electrical resistance of a uniform specimen of the material (measured in ohms)

l is the length of the piece of material (measured in m)

A is the cross-sectional area of the specimen (measured in square metres, m

 

[cm304eex]

THanks that really helpedGuiness DrinkGuiness Guiness Drink