Ray optics is based on the assumption that light travels in a straight line. Diffraction effects (observed when light propagates through small apertures/slits or around small obstacles) disprove this assumption. Yet the ray optics assumption is so commonly used in understanding location and several other properties of images in optical instruments. What is the justification ?

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Solution

The justification is that in ordinary optical instruments, the size of the aperture involved is much larger than the wavelength of the light used.

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Answer the following questions:

(a) In a single slit diffraction experiment, the width of the slit is made double the original width. How does this affect the size and intensity of the central diffraction band?

(b) In what way is diffraction from each slit related to the interference pattern in a double-slit experiment?

(c) When a tiny circular obstacle is placed in the path of light from a distant source, a bright spot is seen at the centre of the shadow of the obstacle. Explain why?

(d) Two students are separated by a 7 m partition wall in a room 10 m high. If both light and sound waves can bend around obstacles, how is it that the students are unable to see each other even though they can converse easily.

(e) Ray optics is based on the assumption that light travels in a straight line. Diffraction effects (observed when light propagates through small apertures/slits or around small obstacles) disprove this assumption. Yet the ray optics assumption is so commonly used in understanding location and several other properties of images in optical instruments. What is the justification?

Q. Answer the following questions: (a) In a single slit diffraction experiment, the width of the slit ismade double the original width. How does this affect the sizeand intensity of the central diffraction band? (b) In what way is diffraction from each slit related to theinterference pattern in a double-slit experiment? (c) When a tiny circular obstacle is placed in the path of light froma distant source, a bright spot is seen at the centre of the shadowof the obstacle. Explain why? (d) Two students are separated by a 7 m partition wall in a room10 m high. If both light and sound waves can bend around obstacles, how is it that the students are unable to see eachother even though they can converse easily. (e) Ray optics is based on the assumption that light travels in astraight line. Diffraction effects (observed when light propagatesthrough small apertures/slits or around small obstacles)disprove this assumption. Yet the ray optics assumption is socommonly used in understanding location and several otherproperties of images in optical instruments. What is the justification?

Which is valid when Fresnal distance is equal to D ( D =distance between the slit and screen]

Diffraction or ray optics

I know that diffraction is valid when it is much less than D ....

Greater than D then ray optics is valid

What if they are equal???

Pls ans in detail ☺

Q. For what distance is ray optics a good approximation when the aperture is

4 m m

and the wavelength of light is

400 n m

Q. When a ray of light travels from an optically denser medium to an optically rarer medium

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