Differentiate between convex mirror and concave mirror.

Convex mirror Concave mirror 1) A convex mirror diverges the light rays 1) A concave mirror converges the light rays 2) The spherical mirror in which the reflection of light takes place at the bulging surface (convex surface) is called convex mirror. 2) The spherical mirror in which the reflection of light takes place at a bent surface (concave surface) is called concave mirror. 3) The focal length is negative in a convex mirror 3) The focal length is positive in a concave mirror 4) The convex mirror produces only virtual images 4) Concave mirror produces both real and virtual images

In the given figure, AB is the incident ray, BC is the refracted ray and MN is the normal at the point of incidence. Which medium is more denser? Why?

The figure represents the refraction of light. The change in the direction of light when it passes from one medium to another is known as the refraction of light. A medium in which the speed of light is less is known as an optically denser medium i.e., a more dense medium. Here, medium 1 is more denser. This is because when a ray of light goes from a rarer medium to a denser medium, it bends towards the normal. Here, as the light ray passes from medium 2 to medium 1 , it bends towards the normal. Hence, we can conclude that medium 1 is more denser here.

State the laws of refraction of light.

The refraction of light on going from one medium to another medium takes place according to two laws which are known as the laws of refraction of light. 1) The incident ray, the refracted ray and the normal to the interface of two transparent media at the point of incidence, all lie in the same plane. 2) The ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant, for the light of a given colour and for the given pair of media. This law is also known as Snell’s law of refraction. If i is the angle of incidence and r is the angle of refraction, then, sin i sin r = constant

Observe the given incomplete diagram. Complete the diagram by drawing refracted rays and show the image formed.

The required diagram is given below: Here, the object is placed between the optical centre O and focus F 1 of a convex lens. Here A ' B ' is the image of the object formed. It is a virtual image as it cannot be captured on the screen. The image is erect and enlarged. It is formed behind the object.