Ray diagram construction for concave mirrors

Presented byObina Johnson Okeny.

Objectives:

• To show how rays travel in order to form images in a concave mirrors.• To show and state the nature of

images formed.

The paths of three rays are known.• Rays traveling parallel to the

principal axis• Rays passing through the principal

focus • Rays passing through the centre of

curvature

C F P

(a) Rays parallel to the principal axis are reflected and they pass through the principal focus

(b) Rays passing through the principal focus (F) will move parallel to the principal axis after reflection

C F P

(c) Ray passing through the centre of curvature (C) are reflected back along their own paths because they are normal to the mirror.

C F P

FC P

I am parallel to the principal axis. Always draw me first

I am the Object

I am re

flected and

pass th

rough F.For me, I pass

through F first

I am reflected parallel to the principal axis

I pass through C

and I am reflected

back along my own

path

Now let us draw a ray diagram for an object beyond C

What is the nature of the image formed?

Imag

e

FC P

I am parallel to the principal axis. Always draw me first

I am the Object

I am re

flected and

pass th

rough

F.

For me, I pass

through F first

I am reflected parallel to the principal axis

Now let us draw a ray diagram for an object at C

I am

the

imag

e

What is the nature of image formed?

FC P

I am parallel to the principal axis.

I am the Object

I am re

flected and

pass th

rough

F.

For me, I pass

through F first

I am reflected parallel to the principal axis

Now the object is between C and F

I am

the

imag

e no

w.

What is the nature of this image?

FC P

I am the Object

Now let us draw a ray diagram for an object at F

We will meet at in

finity to

form a real, inverted

magnified image.

FC P

I am the Object

I am reflected and

pass through F.

For m

e, I p

ass

thro

ugh F

first

I am reflected parallel to the principal axis

I pass through C and I am reflected

back along my own path

Now let us draw a ray diagram for an object between F and P

I am the image.

What is the nature of image formed?

THANK YOU!

obinaokeny@yahoo.com