How Do You Calculate Resistance and Current in a Carbon Block Using Ohm's Law?

AI Thread Summary
To calculate the resistance of a carbon block, the formula R = pL/A is used, where p is resistivity, L is the length, and A is the cross-sectional area. The block measures 3cm in length with a square cross-section of 0.5cm by 0.5cm, leading to an area of 0.25cm². With a potential difference of 8.4V applied, users seek to determine both the resistance and the current through the block. Clarification on the block's shape, described as a cuboid, aids understanding of the problem. This discussion emphasizes the importance of visualizing the geometry for accurate calculations.
LeakyFrog
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Homework Statement


A block of carbon is 3cm long and has a square cross section whose sides are .5cm long. A potential difference of 8.4V maintained across its length.
a)What is the resistance of the block?
b)What is the current in this resistor?


Homework Equations


R=pL/A
where p is resistivity


The Attempt at a Solution


I'm fairly certain i can solve this problem right quick if I could understand what exactly the block looked like. The description just doesn't make sense to me. I'm not sure if you can draw pictures on this or not but a picture would be helpful if someone can make one. Thanks.
 
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From what I've read the block is a cuboid. Imagine a square that's 0.5cm by 0.5cm, now stretch that back in the third dimension by 3cm, and Bob's your uncle. A similar shape to a packet of gum.

Juicy+fruit.gif
 
thanks dude (or dudette)! helped a bunch!
 
No worries mate.
 
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