resistance

IIT JEE 2015 Help › Electricity and magnetism questions › resistance

a resistor is formed in the shape of a hollow, quarter cylinder from a material of resistivity P. The length of cylinder is L, inner and outer radii are r1 and r2 respectively. the resistance of this resistor between the outer and inner radii is...???

#Physics #Electricity and magnetism

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4 Answers

1

Avinav Prakash ·2010-01-16 22:20:28

R=ÏÎ (r1²-r2²)14l
is this the ans?

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1

cute_cat ·2010-01-17 00:03:28

No

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62

Lokesh Verma ·2010-01-23 03:08:03

avinav.. you have found the resistance across the two ends?

What you should do is to use concentric cyllinders.. and then integrate...

It is something like the capacitance of cyllinders..

If you cant then i will reply :)

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11

Tush Watts ·2010-01-23 11:07:29

This is the case of variation of area ,

Considering the series arrangement ,
Elemental resistance dR at a distance x as

dR = P dxA

Current is flowing readily outward ,

dR = P dx2 pie x L

Therefore, R = âˆ« dR = P2 pie L âˆ« dxx
[Taking limits frm r₁ to r₂ ] , we get

R = P2 pie L ln r2r1

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