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In an 20 m deep lake, the bottom is at a...

In an `20` m deep lake, the bottom is at a constant temperature of ` 4^(@)C`. The air temperature is constant at `-10 ^(@)C`. The thermal conductivity of ice in `4` times that water. Neglecting the expansion of water on freezing, the maximum thickness of ice will be

A

` (22)/(11)` m

B

`(200)/(11)` m

C

`20 m`

D

`10` m

Text Solution

Verified by Experts

The correct Answer is:
B
The rate of heat flow is the same through water and ice in the steady state so `(KA(4-0))/(20-x) = (4KA[0-(-10)])/(x) implies x = (200)/(11) m`
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