Question

A glass tumbler containing hot water is kept in the freezer compartment of a refrigerator (temperature < 0°C). If you could measure the temperature of the content of the tumbler, which of the following graphs (Fig.1.2) would correctly represent the change in its temperature as a function of time.

विकल्प

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Answer 1

The hot water in the glass tumbler kept in the freezer will first become cold and the temperature will drop till 0°C. At 0°C, water loses heat equal to the latent heat of fusion till entire water freezes to form ice at 0°C. During this change of state from liquid to solid, the temperature remains constant.
On still further cooling, the temperature of ice slowly falls with time. Therefore, the correct option is (a).