What is the difference between diffraction & refraction?

Question

What is the difference between diffraction & refraction?

Answer 1

Diffraction: http://en.wikipedia.org/wiki/Diffraction

Refraction: http://en.wikipedia.org/wiki/Refraction

Answer 2

"Diffraction" is normally taken to refer to various phenomena which occur when a wave encounters an obstacle. It is described as the apparent bending of waves around small obstacles and the spreading out of waves past small openings.

Very similar effects are observed when there is an alteration in the properties of the medium in which the wave is travelling, for example a variation in refractive index for light waves or in acoustic impedance for sound waves and these can also be referred to as diffraction effects. Diffraction occurs with all waves, including sound waves, water waves, and electromagnetic waves such as visible light, x-rays and radio waves. As physical objects have wave-like properties, diffraction also occurs with matter and can be studied according to the principles of quantum mechanics.

"Refraction" is the change in direction of a wave due to a change in its speed. This is most commonly seen when a wave passes from one medium to another. Refraction of light is the most commonly seen example, but any type of wave can refract when it interacts with a medium, for example when sound waves pass from one medium into another or when water waves move into water of a different depth. Refraction is described by Snell's law, which states that the angle of incidence is related to the angle of refraction by

http://upload.wikimedia.org/math/2/0/a/2...

where

v1 and v2 are the wave velocities through the respective media.

θ1 and θ2 are the angles between the normal (to the interface) plane and the incident waves respectively.

n1 and n2 are the refractive indices

Answer 3

DIFFRACTION - diffraction is bending of light at the corner of an obstacle . eg: DIFFRACTION OF LIGHT

REFRACTION -Refraction is the bending of a wave when it enters a medium where it's speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media. The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's Law

Answer 4

Refraction is the bending of a wave when it passes from one medium to another while diffraction is the bending of a wave around obstacles.  

Answer 5

Refraction is the change in direction of waves which occurs when waves travel from one medium to another. Refraction is always accompanied by a wavelength and speed change. Diffraction is the bending of waves around obstacles and openings. The amount of diffraction increases with increasing wavelength.