Question

If hot water is mixed with cold water

(a) its temperature first increases then become constant

(b) its temperature first decreases then become constant

(c) its temperature increases continuously

(d) first its temperature is uncertain then become constant.

Answer 1

Correct option (b) its temperature first decreases then become constant

Explanation :

When hot water is mixed with cold water, hot water loses heat to cold water and so the temperature of hot water falls and that of cold water rises. When temperature of hot water, due to continuous fall and temperature of cold water due to continuous rise become equal, the temperature becomes constant.