Question

Choose the correct alternative and rewrite the following: 

Inside water, an air bubble behaves ....................

पर्याय

• always like a flat plate

• always like a concave lens

• always like a convex lens

• always like a concave mirror

Answer 1

always like a concave lens

• Inside water, the air bubble behaves like a Concave lens. The concave lenses are known as diverging lenses as the rays diverge after falling on the concave lens.
• The concave lens diverges a straight light beam coming from the source to a diminished, upright, virtual image and forms both real and virtual images.
• The air bubble is a sphere with a convex surface and when light reaches it, the light is reflected within the water as in a concave lens.

The refractive index of air = 1 and

The index of water = 1.33.

Since the water refractive index is greater than air, the air bubbles in the water will behave like a concave lens.