Question

Give the notes of class 10th
subject -physics
chapter 1 LIGHT:REFLECTIONA ND REFRACTION

Answer 1

Hey there,

Some important topics are:

1. Reflection :

Bouncing back of light rays to the same medium when they are falling on a smooth Shiny object.

2.Laws of reflection: 1st Law :

Incident ray and reflected ray all lie in the same plane at same point.

2nd Law :

Angle of incidence is equal to angle of reflection.

3.Refraction:

bending of light when it passes from one medium to another medium.

4.laws of refraction.

5.types of image formed by real image:

Real Image:

Image which is form in the front of mirror and can be obtained on the screen is called real image.

Virtual image :

Image which is formed behind the mirror and cannot be obtained on the screen is called Virtual Image.

6.Types of Mirror:

Plane mirror :

A mirror having a flat surface is called plane mirror.

Spherical Mirror:

Mirrors having curved reflecting surfaces are called spherical mirror.

Uses of Concave Mirror:

1.Uses in torches as search light and headlights of vehicles.Used to see large image of the teeth .Use to focus sunlight in the solar furnace.

7.Radius of Curvature:

The radius of sphere of which the reflecting surface of a spherical mirror is a part is called radius of curvature.

8.Principal axis:

Imaginary line passing through the centre of Curvature and the pole of a spherical mirror is called principal axis.

9.Convex Lens: Spherical mirror with reflecting surface curved outside is called convex mirror.

10.Convex Lens:A lens may have two spherical surfaces bulging out is called convex lens,it is also known as conversing lenses.

11.Concave lens:A lens may have two spherical surfaces bulging out what is double convex lens is also known as converging lenses.

12. Focus of lens: A beam of light parallel is Principal Axis after refraction from convex lens converging to the point on principal axis is denoted by f known as principal Axis concave lens and they focus from a point on the principal axis is known as principal focus.

13. Some important topics mirror formula, Snell's formula, absolute refractive index, lens formula for magnification produced by a lens power of lenses.

14. Near point :The point at closest distance at which an object can be seen clearly by the why is called near point of the eye. The distance of the near point of a normal eye is called distance of the distinct vision it is represent the d for a normal eye. Value of least distance is 25 centimetre.

15.Far point: The most distant point at which an object can be seen clearly is called far point of the eye.

16.Myopia : Eye cannot see distant objects clearly image of the distance image forms in front of retina.

Reason :excessive curvature of eye lens, elongation of eyeball 17.hypermetropia: eye cannot see nearby objects clearly as objects nearby forms behind retina.

18. Refraction: refraction of light by the earth's atmosphere twinkling of stars advance sunrise and delayed sunset flattening of disc of Sun at sunrise and sunset aur due to atmospheric refraction.

19: Image formation:formation of image depends upon the position of the object there are 6 possibilities of the position of object in the case of concave mirror.

hope it has Help !

thank you.

Answer 2

$\huge{\mathfrak{\red{\underline{\underline{REFLECTION}}}}$

The coming back of light rays to the same medium after falling on a body is referred to as Reflection.

$\large{\mathfrak{\red{\underline{\underline{LAWS\:OF\:REFLECTION}}}}$

$\mathcal\blue{\underline{Ist\:law}}$

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

$\mathcal\blue{\underline{IInd\:law}}$

The angle of incidence is always equal to angle of reflection.

${\mathfrak{\red{\underline{\underline{Spherical\:mirrors-}}}}$

$\mathcal\blue{\underline{Important\:terms\:related\:to\:Spherical\:Mirror:-}}$

$\bold\pink{\underline{Pole:-}}$

Midpoint or the centre of the reflecting surface of a spherical mirror is called Pole.

$\bold\pink{\underline{Centre\:of\:Curvature:-}}$

The centre of the hollow sphere of which the given mirror is a part is known as Centre of curvature.

$\bold\pink{\underline{Radius\:of\:Curvature:-}}$

Radius of the sphere of which the given mirror is a part is known as radius of curvature.

$\bold\pink{\underline{Principal\:axis:-}}$

The line joining the centre of curvature and pole is known as Principal Axis.

$\mathcal\blue{\underline{Concave\:Mirror:-}}$

Reflecting surface is curved inwards.

Polishing is done on outer surface.

$\mathcal\blue{\underline{Convex\:Mirror:-}}$

Reflecting surface is curved outwards.

Polishing is done on inner surface.

$\mathcal\red{\underline{Uses\;of\;Concave\;Mirror:-}}$

1 Used in torches, search light and headlight of vehicle.

2. Used to see large image of face as shaving mirror

3. Used by dentist to see large images of the teeth

4. Large concave mirror used to focus sunlight (heat) in solar furnaces.

$\mathcal\red{\underline{Uses\;of\;Convex\;Mirror:-}}$

Used as rear-view mirror in vehicles because it gives erect image. Italso helps the driver to view large area.

$\mathcal\red{\underline{Sign\;Convention\;for\;Reflection\;by\;Spherical\;Mirror:-}}$

1. The object is always placed to the left side of mirror.
2. All distance should be measured from pole (P); parallel to principal axis.
3. Take ‘P’ as origin. Distances measured

Right of the origin (+x-Axis) are taken positive

Left of the origin (–x-Axis) are taken negative

Perpendicular to and above principal axis (+y-Axis) are taken positive

.

Perpendicular to and below principal axis (–y-Axis) are taken negative.

$\mathcal\red{\underline{Mirror\;Formula:-}}$

$\huge{\boxed{\bf{\frac{1}{f}=\frac{1}{v}+\frac{1}{u}}}$

f = distance between F and Pole

v = distance of image from Pole

u = distance of object from Pole

R = distance between centre of curvature and pole.

$\mathcal\red{\underline{Magnification:-}}$

It is expressed as the ratio of the height of the image to height of the object.

${\boxed{\bf{m=\frac{height\;of\;image}{height\;of\;object}}}$

${\boxed{\bf{m = \frac{h_{i}}{h_{o}} =\frac{-v}{u}}}$

$\mathcal\blue{\underline{Convex\;lens:-}}$

1. Bulging outwards.

2. Converging lens.

$\mathcal\blue{\underline{Concave\;lens:-}}$

1. Bulging inwards.

2. Diverging lens.

A lens bounded by two spherical surfaces, curved inwards is known asdouble concave lens (or simply concave lens)

It is also known as diverging lens because it diverges the light.