A student takes some water in a beaker and heats it over a flame for determining its boiling point. He keeps on taking its temperature readings. He would observe that the temperature of water :(1) keeps on increasing regularly(2) keeps on increasing irregularly(3) first increases slowly, then decreases rapidly and eventually becomes constant(4) first increases gradually and then becomes constant.

Correct Answer: (4) first increases gradually and then becomes constant.

Explanation: When we boil the water, its temperature rises gradually but after some time it becomes constant. During phase transformation temperature of the water becomes constant because all the heat supplied to increase the temperature will be utilizing in changing the state by overcoming the force of attraction between the particles.