if a convex lens of focal length 20cm and a concave lens of focal length 30cm kept in contact with each other first what will be the focal length of the combination second what will be the power of the combination third what will be the behaviour of the combination

hi there!

your question asks at which segment does freezing occur.

since we're talking about water, the freezing point of water will be 32 degrees fahrenheit or below.

hope this ! ~

blue light is scattered in different directions by the tiny molecules of air. blue is scattered more than other colours because it has a shorter distance to travel which results in smaller waves. this is why we see a blue sky most of the time.