This could be easily understood with the idea of plane wavefront. Huygens have given the concept of wavefront. That has been defined as the locus of all points in the medium which get vibrated simultaneously and are vibrating in phase. More over ray concept is old one. Any ray of light will be normal to the new concept ie wavefront.
So as ray hits normally on the surface, then all points on the wavefront hit simultaneously on the surface of separation and secondary wavelets would be produced at the same instant. So the wavefront would continue as it is. Hence ray goes un deviated. On the other hand if the ray hits at an inclined position with the surface of separation, then the wavefront would be falling in an inclined way. So those reach earlier the surface would start giving rise to secondary wavelets which would traverse at less speed in the other media. Thus the successive points giving rise to secondary wavelets would make the wavefront to be inclined at a different angle with the surface of separation. Hence the ray gets refracted.
We can imagine as if a military parade is crossing the border right from cemented road to a region full of sand. On cemented road one can walk easily so at high speed. But in sand speed would be reduced. So the parade as a whole would change the direction of marching forward.
terms realated to refraction of light are * interface * incident ray * refracted ray * point of incidence *normal *angle of incidence * angle of refraction *angle of deviation
The amount of bending that a light ray experiences can be expressed in terms of the angle of refraction (more accurately, by the difference between the angle of refraction and the angle of incidence). A ray of light may approach the boundary at an angle of incidence of 45-degrees and bend towards the normal. If the medium into which it enters causes a small amount of refraction, then the angle of refraction might be a value of about 42-degrees. On the other hand if the medium into which the light enters causes a large amount of refraction, the angle of refraction might be 22-degrees. (These values are merely arbitrarily chosen values to illustrate a point.) The diagram below depicts a ray of light approaching three different boundaries at an angle of incidence of 45-degrees. The refractive medium is different in each case, causing different amounts of refraction.
The longer the wavelength, the greater the angle of refraction.
There will be refraction when light passes from one substance to the other (for example, from air to water), when the two substances have different indices of refraction, and when light passes the surface at an angle. In other cases, there is no refraction.
If a beam of light enters a substance with a higher density than air and at an angle, the light is refracted so that an object on the far side of the substance appears to be closer to the observer. If the density of the substance is lower than that of air, the light is refracted away from the observer and the object being viewed appears to be farther away.
terms realated to refraction of light are * interface * incident ray * refracted ray * point of incidence *normal *angle of incidence * angle of refraction *angle of deviation
The angles of light are the result of the law of sines: sine( incidence angle)/speed of incidence = sine(refraction angle)/ speed of refraction
The speed of light in a single substance doesn't tell you anything about refraction. The angle of refraction at the boundary between two substances depends on the speed of light in both of them ... and also, let us not forget, on the angle of incidence at the boundary.
Reflection is a change of the angle of light without a change of medium. Refraction is a change of the angle of light with a change of medium.
The angle of refraction is larger. BOOBIES
The amount of bending that a light ray experiences can be expressed in terms of the angle of refraction (more accurately, by the difference between the angle of refraction and the angle of incidence). A ray of light may approach the boundary at an angle of incidence of 45-degrees and bend towards the normal. If the medium into which it enters causes a small amount of refraction, then the angle of refraction might be a value of about 42-degrees. On the other hand if the medium into which the light enters causes a large amount of refraction, the angle of refraction might be 22-degrees. (These values are merely arbitrarily chosen values to illustrate a point.) The diagram below depicts a ray of light approaching three different boundaries at an angle of incidence of 45-degrees. The refractive medium is different in each case, causing different amounts of refraction.
The angle of incidence.
The longer the wavelength, the greater the angle of refraction.
There will be refraction when light passes from one substance to the other (for example, from air to water), when the two substances have different indices of refraction, and when light passes the surface at an angle. In other cases, there is no refraction.
If a beam of light enters a substance with a higher density than air and at an angle, the light is refracted so that an object on the far side of the substance appears to be closer to the observer. If the density of the substance is lower than that of air, the light is refracted away from the observer and the object being viewed appears to be farther away.
The angle of incidence is the angle at which a ray of light (which is not at right angles to a surface) strikes a surface. The angle of refraction is the angle at which a ray of light, having passed through a surface, travels through the body of a substance. Normally the angle of incidence and the angle of refraction are not the same.
The angle of refraction is the angle between the refracted ray and the normal (a perpindicular line to the tangent and the plane of the surface). A ray that enters at the normal angle leaves at the normal angle; there is no angle between the ray and the normal, so it is 0o.