Could you explain the concepts behind this question

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The discussion focuses on understanding the resistance of a truncated cone using Ohm's Law. The key concept involves modeling the cone as a series of thin discs, which allows for the calculation of resistance based on varying current density along the cone's height. The resistance formula derived is R = (density/pi)*(h/ab), where density refers to resistivity, and a and b are the radii of the cone's ends. Participants encourage breaking the problem down into manageable parts to facilitate understanding. This approach helps clarify the relationship between geometry and electrical resistance in the context of the problem.
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I'm trying this question. i know that resistance is the concept of ohms law together with electric potential giving rise to V/I but i can't seem to know how to start. Please advice




A material of resistivity r is formed into the shape of a truncated cone of altitude h. The bottom end has radius b , and the top end has radius a . Assume
that the current is distributed uniformly over any circular cross section of the cone, so that
the current density does not depend on radial position. (The current density does vary
with position along the axis of the cone.) Show that the resistance between the two ends is
described by the expression: R= (density/pi)*(h/ab)
 
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welcome to pf!

hey jimmy! welcome to pf! :smile:

(have a pi: π :wink:)

pretend the cone is a series of very thin discs of height dh :wink:
 
alright thanks! i'll try that
 
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