Advertisements
Advertisements
प्रश्न
A thin prism is made of a material having refractive indices 1.61 and 1.65 for red and violet light. The dispersive power of the material is 0.07. It is found that a beam of yellow light passing through the prism suffers a minimum deviation of 4.0° in favourable conditions. Calculate the angle of the prism.
Advertisements
उत्तर
The refractive indices for red and yellow lights are μr = 1.61 and μy = 1.65, respectively.
Dispersive power, ω = 0.07
Angle of minimum deviation, δy = 4°
Now, using the relation \[\omega = \frac{\mu_v - \mu_r}{\mu_y - 1},\] we get
\[ \Rightarrow 0 . 07 = \frac{1 . 65 - 1 . 61}{\mu_y - 1}\]
\[\Rightarrow \mu_y - 1 = \frac{0 . 04}{0 . 07} = \frac{4}{7}\]
Let the angle of the prism be A.
Angle of minimum deviation, δ = (μ − 1)A
\[\Rightarrow A = \frac{\delta_y}{\mu_y - 1} = \frac{4}{\left( \frac{4}{7} \right)} = 7^\circ\]
Thus, the angle of the prism is 7°.
APPEARS IN
संबंधित प्रश्न
A ray PQ incident on the face AB of a prism ABC, as shown in the figure, emerges from the face AC such that AQ = AR.

Draw the ray diagram showing the passage of the ray through the prism. If the angle of the prism is 60° and refractive index of the material of prism is `sqrt3` , determine the values of angle of incidence and angle of deviation
Two monochromatic rays of light are incident normally on the face AB of an isosceles right-angled prism ABC. The refractive indices of the glass prism for the two rays '1' and '2' are respectively 1.38 and 1.52. Trace the path of these rays after entering through the prism.

State any two difference between the primary rainbow and secondary rainbow
For any prism, prove that :
'n' or `mu = sin((A + delta_m)/2)/sin(A/2)`
where the terms have their usual meaning
Draw the ray diagram showing refraction of light through a glass prism and hence obtain the relation between the refractive index μ of the prism, angle of prism and angle of minimum deviation.
Describe an activity to show that the colours of white light splitted by a glass prism can be recombined to get white light by another identical glass prism. Also, draw a ray diagram to show the recombination of the spectrum of white light.
Give the formula that can be used to determine refractive index of materials of a prism in minimum deviation condition ?
Can the dispersive power \[\omega = \frac{\mu_u - \mu_r}{\mu - 1}\] be negative? What is the sign of ω if a hollow prism is immersed into water?
A prism can produce a minimum deviation δ in a light beam. If three such prisms are combined, the minimum deviation that can be produced in this beam is _______________.
By properly combining two prisms made of different materials, it is possible to
(a) have dispersion without average deviation
(b) have deviation without dispersion
(c) have both dispersion and average deviation
(d) have neither dispersion nor average deviation
Two prisms of identical geometrical shape are combined with their refracting angles oppositely directed. The materials of the prisms have refractive indices 1.52 and 1.62 for violet light. A violet ray is deviated by 1.0° when passes symmetrically through this combination. What is the angle of the prisms?
A thin prism of crown glass (μr = 1.515, μv = 1.525) and a thin prism of flint glass (μr = 1.612, μv = 1.632) are placed in contact with each other. Their refracting angles are 5.0° each and are similarly directed. Calculate the angular dispersion produced by the combination.
A ray of light is incident on a prism whose refractive index is 1.52 at an angle of 40°. If the angle of emergence is 60°, calculate the angle of the prism.
A narrow beam of monochromatic light, PQ, is incident normally on one face of an equiangular glass prism of refractive index 1.45. When the prism is immersed in a certain liquid, the ray makes a grazing emergence along the other face (See figure). Find the refractive index of this liquid. 
What is meant by the dispersive power of transparent material?
An equilateral glass prism has a refractive index 1.6 in the air. Calculate the angle of minimum deviation of the prism, when kept in a medium of refractive index `4sqrt(2)"/"5.`
Define angular dispersion.
When a ray of white light is incident obliquely on the first surface of a prism, then ______.
What is meant by a thin prism?
