shaving mi.rorS

in the reflecting telescope, microscope and headlamps of automobiles

ake-up or

reflectors in

oroducing laser light:

proo ht and spot light. (ln tact, parabolic mirórs are used more effectively).

dentists and eye alists in ophthalmoscopes

es

search ligh

iva VOC

ce cf experiment 

lhe

For example,5

Experiment No.  (Glass Slab)

reflection of light? Explain why we can not see in the dark?

, of light strikes a Smooth shinning surface, it returns back in the same megium in a

light and for Wihen a ray of

ular direction.

irection. This phenomenon 1s called reflection. we cannot see any object in the dark

there 1S no l1ght to reflect.

Peseribe he two laws of eflection.

.r.t. glass?

The angle of inc

y Dair of materials (mediums).

incident ray, the reflected ray and the normal all lie in the same plane.

ncidence (1) 1s equal to the angle of reflection (r), for all wavelengths and ior

What is normal?

is aperpendicul to the

Maw many types of reflections are there? Which type of reflection takes place by walls?

no-regular (specular) and iregular (diffused). Walls suffer diffuse reilection.

reflecting surface at the point of incidence.

What is refraction?

hen a ray a of light enters from one medium to another medium, its changes it path. This

ending of a ray of light causing a change in direction is called refraction.

violet light is What are the two laws of refraction?

gth is calie The incident ray, the refracted ray and the normal all lie in the same plane.

The ratio of the sine of angle of incidence to the sine of angle of refraction

constant.

is 4/3. Wha Sn6

=D12

SinO

Hhere n2 1S called refractive index of medium 2 w.r.t. (With respect to) medium 1.

What is optically denser medium?

dmedium when rays of light bend towards the normal, after reiraction, the transparent me-

Lm is said to be optically dense.

hat is refractive index"?

llOled by T e ratio of the speed of light in a vaccum (c) to the speed oI lignt in a transparent medium

.Thus n-C

ad bends, a

produce im

Gve formulae

to calculate refractive index of glass.

Sin G

Sin , (Sne!l's law or Alhozen's law)

real depth For For a glass slab, n =

4pparent depth h2