Advertisements
Advertisements
प्रश्न
With the help of neat diagram, explain how non-polar dielectric material is polarised in external electric field of increasing intensity. Define polarisation in dielectrics.
उत्तर
If a dielectric (non-polar) molecule is placed in an external electric field, a small induced dipole moment is created because the positive charge in each atom is pushed in the direction of the field and negative charge is pushed in the opposite direction as shown in the figure.
Polarization is the amount of induced surface charge per unit area or the surface density of polarization charges appearing at right angles to applied external electric field.
APPEARS IN
संबंधित प्रश्न
For a glass plate as a polariser with refractive index 1.633, calculate the angle of incidence at which light is polarised.
If the critical angle of a medium is sin-1(3/5), find the polarising angle.
Find an expression for intensity of transmitted light when a polaroid sheet is rotated between two crossed polaroids. In which position of the polaroid sheet will the transmitted intensity be maximum?
A beam of unpolarised light is incident on a glass-air interface. Show, using a suitable ray diagram, that light reflected from the interface is totally polarised, when μ = tan iB, where μ is the refractive index of glass with respect to air and iB is the Brewster's angle.
Using the phenomenon of polarisation, show how the transverse nature of light can be demonstrated.
Show, via a suitable diagram, how unpolarised light can be polarised by reflection.
The refractive indices of glass and water w.r.t. air are 3/2 and 4/3 respectively. Determine the refractive index of glass w.r.t. water.
A ray of light passes from a vacuum to a medium of refractive index (μ). The angle of
incidence is found to be twice the angle of refraction. The angle of incidence is _______.
A) `cos^(-1)(mu/2)`
B) cos−1(μ)
C) `2 cos^(-1) (mu/2)`
D) `2 sin^(-1) (mu/2)`
What is the value of refractive index of a medium of polarising angle 60°?
The glass plate of refractive index 1.732 is to be used as a polarizer, its polarising angle is _______.
Show using a proper diagram how unpolarised light can be linearly polarised by reflection from a transparent glass surface.
State any two methods by which ordinary light can be polarised
Unpolarised light is incident on a polaroid. How would the intensity of transmitted light change when the polaroid is rotated?
A beam of light is incident at the polarizing angle of 35° on a certain glass plate. The refractive index of the glass plate is :
A ray of light is incident on a transparent medium at a polarizing angle. What is the angle between the reflected ray and the refracted ray?
A ray of ordinary light is travelling in air. It is incident on air glass pair at a polarising angle of 56°. Find the angle of refraction in glass.
Greenlight is an incident at the polarising angle on a certain transparent medium. The angle of refraction is 30°.
Find
(i) polarising angle, and
(ii) refractive index of the medium.
What is polarisation?
Discuss polarisation by selective absorption.
What is plane polarised light?
What is unpolarised light?
State Brewster’s law.
What is the angle of polarisation and obtain the equation for an angle of polarisation?
Discuss about Nicol prism.
A plane mirror produces a magnification of
Polarisation of light is the only phenomenon that establishes ______.
