C HAPTER . (a) Reflected light: (wavelength, frequency, speed same as incident light) # = nm, + = . Hz, c = . m s – (b) Refracted light: (frequency same as the incident frequency) + = .
Hz v = ( c/n ) = . × m s – , # = ( v/ + = nm . (a) Spherical (b) Plane (c) Plane (a small area on the surface of a large sphere is nearly planar). .
(a) . × m s – (b) No. The refractive index, and hence the speed of light in a medium, depends on wavelength. [When no particular wavelength or colour of light is specified, we may take the given refractive index to refer to yellow colour.] Now we know violet colour deviates more than red in a glass prism, i.e.
n v > n r . Therefore, the violet component of white light travels slower than the red component. . .
In corpuscular (particle) picture of refraction, particles of light incident from a rarer to a denser medium experience a force of attraction normal to the surface. This results in an increase in the normal component of the velocity but the component along the surface is unchanged. This means c sin i = v sin r or v c r i sin sin . Since n > , v > c.