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WATER is optically DENSER as speed of light is less in water.

2.25 × 10⁸ ms^-1 < 3 × 10⁸ ms ^-1

speed of light in Water speed of light in Air.

bends towards the normal

False Water is optically denser than air.

(a) Water is optically denser than air.

(b) Air is optically rarer than glass.

(c) When a ray of light travels from water to air, it bends away from the normal.

(d) When a ray of light travels from air to glass, it bends towards the normal.

(e) When white light passes through a prism, it disperses

(f) The splitting of white light into its constituent colours is called dispersion.

(g) A concave mirror is obtained on silvering the outer surface of a part of a hollow glass sphere.

(h) Radius of curvature of a spherical mirror is two times its focal length.

(i) The angle of incidence for a ray of light passing through the center of curvature of a spherical mirror is 0°

(j) A convex mirror always forms a virtual image.

(k) A concave mirror forms a virtual image for an object placed between pole and focus.

REAL IMAGE. “When rays of light after reflection or refraction actually meet at some other point” the image is real. Concave mirror.

Except between pole and focus, the image formed is REAL.

True A virtual image formed by a spherical mirror is always erect and situated behind the mirror.

The image formed by a plane mirror is laterally inverted, upright, of the same size and is formed far behind the mirror as the object is in front of it.

(i) The image formed is erect. 

(ii) The image is of the same size as that of the object. 

(iii) The image is laterally inverted. Right side appears to be left and left side appeared to be right.

The distance of man from the mirror is

2. 3 m

Angle of incidence is 0°. Since angle of incidence is’the angle between incident ray and normal. Direction of reflected ray is along BA opposite to the direction of incident ray.

The angle of incidence will be :

3. 35°

The angle of reflection will be: 

1. 30° 

The angle between the incident ray and the reflected ray is 

 3. 60° 

Spherical mirror. “A mirror which is made from a part of a hollow sphere is called SPHERICAL MIRROR.

The seven colors in the spectrum of sunlight in order, are represented as VIBGYOR

The property of splitting of white light into its seven constituent colors is known as dispersion.

A piece of paper appears white in sunlight because it reflects light of all the colours. It would appear red when viewed in red light.

Laws of reflection :

(1) The incident ray, the reflected ray, and the normal ray at the point of incidence lie in the same plane.

(2) The angle of incidence i is equal to the angle of reflection  i.e. ∠i = ∠r

Spectrum is the band of colors obtained on a screen when white light passes through a prism and splits into its constituent colors. The colors of the spectrum are violet (V), indigo (1), blue (B), green (G), yellow (Y), orange (O), and red (R). The order of the spectrum is VIBGYOR.

(a) Blue + Green = Cyan 

(b) Red + Blue + Green = White 

(c) Red + Blue = Magenta 

(d) Green + Red = Yellow

Primary colours are the colours of light by mixing which white light is obtained. 

They are : 

(i) red 

(ii) green and 

(iii) blue. Red + Green + Blue = White

Reflection of light— When light strikes a polished surface it comes back in the same medium, is called reflection of light.

(i) If a red rose is seen in green light, it appears black. The reason is that the rose absorbs the green light falling on it and reflect none. 

(ii) If a red rose is seen in red light, it appears bright red. This is because the rose reflects the red light falling on it and absorbs none of it.

True Rays of light incident parallel to the principal axis pass through the focus after reflection from a concave mirror.

The image formed by a concave mirror is of the same size as the object, if the object is placed at the center of curvature.

A red rose is seen in green light. It will appear. 

4. black

True The depth of a pond, when seen from above, appears to be less.

(a) A dentist uses CONCAVE MIRROR. 

(b) Convex mirror.

True At the point of incidence, a line drawn at right angles to the surface, separating the two media, is called the normal.

False The angle formed between the normal and the refracted ray is known as the angle of incidence.

False Light travels in the same straight line path while passing through different media.

REFRACTION OF LIGHT: “The change in direction of path of light when it passes from one transparent medium to another is called REFRACTION OF LIGHT.”