Resistance Level 2 - HELP NEEDED!!

[james1985]

hey,

I am currently completing City & Guilds level 2 and stumbled across the below questions and scratching my head...

1. Electric Fire element has a length of 10m, a cross section area of 0.5mm2 and resistance of 50 ohms - calculate resistivity of material used.

Thanks

 

[Pete999]

Ok so am incorrect in saying the answer is 2.5?

Think so yes, just thinking I used to be good at this sort of thing, age certainly take it's toll on the memory. Hang on til Dave gets back don't want to add to the confusion.

 

[telectrix]

p = (R x L)/ A

 

[The Ghost]

Its fairly difficult to write the formula and/or a worked example so here is one. Hope it helps. It is simple but you need a sci. calculator.

 

[telectrix]

or here:
Resistance and Resistivity - http://hyperphysics.phy-astr.gsu.edu/hbase/electric/resis.html

bear in mind that in that example, csa is in sq.cm.

 

[The Ghost]

Sorry it's sideways but you can download it and turn it upright

 

[james1985]

Thanks once again gents, certainly saved me a massive head ache