Question

The concave reflecting surface of a torch got rusted. What effect would it have on the beam of light from the torch?

Answer 1

Hint:The reflecting surface of a torch is given as concave. Concave surface refers to those surfaces in which the reflecting surface is the inward curved surface and the other bulged surface is silvered or coated with other substances. If any reflecting surface is damaged then the intensity of the reflected light decreases from that surface.

Complete answer:
Concave surface of any substance refers to the curved surface of a spherical mirror. The light gets converged after reflecting from this substance and hence are also known as the converging surfaces. Rusting of any surface refers to the chemical corrosion of the substance due to water, moisture, and air on the surface of iron. Hence, when it occurs on the concave reflecting surface of the torch removes some of its reflecting ability.

Thus, when the light falls on the reflecting surface a lesser amount of light gets reflected from the corroded surface. The intensity of the light gets lesser due to the corrosive surface. Eventually it leads to less brightness of the light from the torch.So, we can conclude that the light from a rusted concave reflecting surface of a torch produces light of less brightness and the intensity of the beam of ray from it is less.

Note: It can be stated that the brightness of a light depends on its capacity to reflect light. The surfaces which are less dark or more shiny produce more light. As the rusting surface is darker, mostly brown in colour, it reflects less light. Hence the intensity and the amount of reflected light is less from it.