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Equivalent thermal conductivity of figur...


Equivalent thermal conductivity of figure given below will be given that length of eachh cylinder is l and area of cylinder having thermal conductivity `K_(1)` & `K_(3)` is A while middle cylinder is having `K_(2)`.

A

`(5)/(2[(1)/(K_(1))+(1)/(2K_(2))+(1)/(K_(3))])`

B

`(1)/(((1)/(K_(1))+(1)/(2K_(2))+(1)/(K_(3))))`

C

`(2)/(5[(1)/(K_(1))(1)/(2K_(2))+(1)/(K_(3))])`

D

none of these

Text Solution

Verified by Experts

The correct Answer is:
A
`(l)/(K_(1)A)+(l)/(2K_(2)A)+(l)/(K_(3)A)=(l)/(KA)+(l)/(2K_(A))+(l)/(KA)`
`(5)/(2K)=((1)/(K_(1))+(1)/(2K_(2))+(1)/(K_(3)))`
`K_(eq)=(5)/(2((1)/(K_(1))+(1)/(2K_(2))+(1)/(K_(3))))`
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