1. LIGHT: Geometric Optics
Radhabai Kale mahila mahavidyalaya,ahmednagar Department of Physics
LIGHT: Geometric Optics
Presented By
Prof. Pawar Sir

2. The Ray Model of Light
Light travels in straight lines under a wide variety of circumstances
Light travels in straight line paths called RAYS

3. Optical Instruments: Refractive

4. CONVERGING LENS Causes parallel rays to converge
Produces real and virtual images.
Focal Length is positive.

5. Ray Tracing for Converging Lens
Ray 1: Parallel emerge through F
Ray 2: Through F emerge Parallel
Ray 3: Straight through center

6. The Lens Equation 1/do + 1/di = 1/f m = hi/ho = - di/do ho/hi = do/di
m is magnification
ho/hi = do/di

7. DIVERGING LENS Causes parallel rays to diverge
Produces only small-virtual images.
Focal Length is negative.

8. Ray Tracing for Diverging Lens
Focal length is negative for any diverging instrument.
Image distance is negative for virtual images.
Virtual image produced will be smaller than object.

9. Angular Magnification

10. Who invented the telescope?

11. Refracting Telescope

12. Compound Microscope
The eyepiece is placed such that the image formed by the objective falls at first focal point of the eyepiece. The light thus emerges as parallel rays.

13. Can you explain this?

14. Total Internal Reflection
Red light is incident on the glass-air boundary at an angle greater than the critical angle.
although red, when compared to blue and yellow, has the lower index of refraction.

15. Can you explain this?
The pattern formed is from a converging lens.

16. Spherical Aberation

17. Chromatic Aberration Each color has a different focal point.
The refractive index is different for each wavelength.

18. Reflection Law of Reflection
The angle of incidence equals the angle of reflection
The incident and reflected rays lie in the same plane with the normal to the surface

19. Diffuse vs Specular Reflection
Diffuse Reflection
Light incident upon a rough surface
Law of reflection still holds; Normals not ll.
Specular Reflection
Mirror like reflection
All Normals are parallel

20. Image formation by a Plane Mirror
Image distance equals the object distance.
Image size equals the object size.
Virtual image formed.

21. Optical Instruments: Reflective

22. CONVEX MIRROR Produces only small-virtual images.
Focal Length and Radius are negative.
Anti-Theft, Rear-View, Safety

23. CONCAVE MIRROR Produces both Real and Virtual Images
Real image formed by Converging Rays
Virtual image formed by Diverging Rays
Produces both Real and Virtual Images
Real images can be magnified or reduced
Virtual images are always magnified.

24. CONCAVE MIRROR Real Virtual Real images can be magnified or reduced
Virtual images are always magnified.

25. Equations to Apply f = r/2 ho/hi = do/di 1/do + 1/di = 1/f
f is focal length
r is radius
ho/hi = do/di
h is height
d is distance
o is object
i is image
1/do + 1/di = 1/f
m = hi/ho = - di/do
m is magnification