Question

Why are we able to sip hot tea or milk faster from a saucer rather than a cup?

NCERT Class IX
Sciences - Main Course Book

Chapter 1. Matter in our Surroundings

Answer 1

we know, the rate of vaporization of a liquid is directly proportional to the surface area of the liquid. Since surface area of tea or milk in a saucer is more than that in a cup, so rate of vapourization is more in case of the saucer. Since, the liquid vaporizes by taking latent heat from the liquid itself, hence it becomes cooler. Thus liquid in saucer cools faster.

Answer 2

Evaporation depends on surface area.Evaporation is directly proportional to the surface area, the more the surface area, the more is evaporation. When we put hot tea/milk in a saucer then the surface area increases.Hence it is faster.