Surface

Dew formation occurs when water vapor in the air comes into contact with a cooler surface, like a cold drink bottle. As the temperature of the surface is lower than the dew point of the surrounding air, the water vapor cools and condenses into liquid water droplets on the surface of the bottle. This process is called condensation.

The correct option is (C): condensation

A lens that has two spherical surfaces both curved inwards is known as a double concave lens. In this type of lens, both surfaces are concave, meaning they curve inward toward the center of the lens. This causes the light to diverge as it passes through. In contrast, a double convex lens has both surfaces curved outward, while plano-concave and plano-convex lenses have one flat surface and one curved surface. Thus, the correct answer is double concave.

The correct option is (A): double concave