Question

When we pour cold water in a glass after sometime we find droplet on the glass Same way when we take a glass from fridge with out water even then we find droplets on the glass why

Answer 1

It's called condensation phenomenon.

You know there is air in atmosphere,a mixture of gases and they tend to condense(convert to liquid) at lower temperatures.

So when cold water is poured in a container, it has lower temperature and so eventually it decreases the temperature of surroundings.

And hence the temperature decreases of surrounding. And so the air in contact gets condensed i.e. Gets converted into liquid and hence the nearest air is converted to liquid and gets stuck on Surface of container.