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The thermal conductivity of copper is 4 ...

The thermal conductivity of copper is 4 times that of brass. Two rods of copper and brass having same length and cross-section are joined end to end. Free and of copper is at `0^(@)C` and free end of brass is `100^(@)C`. What is the temperature of junction ?

A

`20^(@)C`

B

`40^(@)C`

C

`80^(@)C`

D

`10^(@)C`.

Text Solution

Verified by Experts

The correct Answer is:
A
Here area and thickness is same.
If T is temperature of interface, then
`k_(1)(100-T)=4k_(1)(T-0)`
`100-T=4T`
`rArrT=20^(@)C`
Thus correct choice is (a).
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