TOPIC – RAY OPTICS

INTRODUCTIONMIRRORS AND REFLECTION OF LIGHTLENS AND REFRACTION OF LIGHTDISPERSION AND SCATTERING OF LIGHTOPTICAL INSTRUMENTS

CONTENTS

Human eye responds to very small portion, known as visible part of electromagnetic spectrum. The visible part of the electromagnetic spectrum consisting of wavelength ranging from 4000 A to 7600A is known as light. We see this beautiful world and the natural phenomena with the help of light. Everything appears dark in the absence of light.

Light travel with the speed of .in air or vacuum. True nature of light is mystery even today. Sun is natural source of light.

INTRODUCTION

Thermal source of light:- A hot source which emits light containing a whole continues range of visible wavelength is known as thermal source of light. For example:- bulb, an oil lamp and burning candle

Gas discharge source of light:- if filled source which on application of potential difference across its electrodes emits light of a particular color is known as gas source of light. for example:- neon bulb, sodium vapour lamp

SOURCE OF LIGHT

The phenomenon of bouncing back of light in the same medium when the light falls on the surface is known as reflection of light.

Reflection of light obeys certain laws known as laws of reflection.

LAWS OF REFLECTION:-1. Angle of incidence is equal to angle of reflection i.e. angle i= angle r

2. The incidence ray ,reflected ray and normal to the reflecting surface at the point of incidence are coplanar.

REFLECTION OF LIGHT

Spherical mirrors are the reflecting part of spherical surface. These are of two types as follows:-

1. Concave mirror:- Concave mirror is a part of a hollow sphere whose outer part is silvered and inner part becomes reflecting surface.

2.Convex mirror:- Convex mirror is a part of a hollow sphere whose inner part is silvered and the outer part becomes reflecting surface.

SPHERICAL MIRRORS

1. Center of curvature2. radius of curvature3.pole (vertex)4.principal axis5.principle section6. aperture7. principal focus8. focal length9. focal plane

IMPORTANT TERMS IN SPHERICAL MIRRORS

Rules of sign conventions are as follows:-1. All the distance are measured from pole of

the spherical mirror.2.Distance measured in the direction of the

incidence light are taken as positive whereas distance measured in the direction opposite to that of the incident light is taken as negative.

3. The upward distance perpendicular to the principal axis are taken as positive while the downward distance are taken as negative.

NEW SIGN CONVENTIONS

The distance between the pole of the mirror and the position of object on the principal axis is represented by u.

The distance between the pole of the mirror and the position of the image on the principal axis is represented by v.

Focal length is represented by f.

MIRROR FORMULA AND MIRROR EQUATION

Linear magnification produced by a mirror is defined as the ratio of the size (or height) of the image to the size of object.

It is denoted by m.

Some conclusions:-Positive magnification means both object and image

are upright.Negative magnification means object and image have

different orientation.

LINEAR MAGNIFICATION

MICROSCOPETELESCOPE

APPLICATIONS OF RAY OPTICS

Thank YOU…!!!!!!