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Water contained in a jar at room tempera...

Water contained in a jar at room temperature `(20^(@)C)` is intended to be cooled by method -`I` or method `II` given below:
Method -`I` : By placing ice cubes and allowing it ito float.
Method-`II` : By wrapping ice cubes in a wire mesh and allowing it to sink.
Choose best method(s) to cool the water.

A

Method- `I` from `20^(@)C` to `4^(@)C`

B

Method- `I` from `4^(@)C` to `0^(@)C`

C

Method- `II` from `20^(@)C` to `4^(@)C`

D

Method- `II` from `4^(@)C` to `0^(@)C`

Text Solution

Verified by Experts

The correct Answer is:
A, D
Initially (above`4^(@)C`), a decreases in temperature , increases the density of water and consequently it descends , replacing the relatively warm water. Convention currents set up in this way demands the location of ice to be on the water surface.
Below `4^(@)C` , a decrease in temperature decreases the water density and as a result it ascends up displacing the relatively warm water, To setup convented currents in this way , the position of ice cubes should be at the bottom.
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