Advertisements
Advertisements
Question
The equation \[\omega = \frac{\mu_u - \mu_r}{\mu - 1}\] was derived for a prism having small refracting angle. Is it also valid for a prism of large refracting angle? Is it also valid for a glass slab or a glass sphere?
Advertisements
Solution
Dispersive power depends on angular deviation, and angular deviation is valid only for a small refracting angle and a small angle of incidence. Therefore, dispersive power is not valid for a prism of large refracting angle. It is also not valid for a glass slab or a glass sphere, as it has a large refracting angle.
APPEARS IN
RELATED QUESTIONS
A ray PQ incident on the refracting face BA is refracted in the prism BAC as shown in the figure and emerges from the other refracting face AC as RS such that AQ = AR. If the angle of prism A = 60° and refractive index of material of prism is `sqrt3 `. Calculate angle θ.

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.

What is the cause of dispersion of light
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
Figure shows a ray of light passing through a prism. If the refracted ray QR is parallel to the base BC, show that (i) r1 = r2 = A/2 and (ii) angle of minimum deviation, Dm = 2i − A.

Give the formula that can be used to determine refractive index of materials of a prism in minimum deviation condition ?
If three identical prisms are combined, is it possible to pass a beam that emerges undeviated? Undispersed?
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.
The minimum deviations suffered by, yellow and violet beams passing through an equilateral transparent prism are 38.4°, 38.7° and 39.2° respectively. Calculate the dispersive power of the medium.
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.
The deviation produced for violet, yellow and red lights for crown glass are 3.75°, 3.25° and 2.86° respectively. Calculate the dispersive power of the crown glass.
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.
What is meant by the dispersive power of transparent material?
Define angular dispersion.
The refractive indices of material for red, violet and yellow colour light are 1.52, 1.62 and 1.59 respectively.
Calculate the dispersive power of the material. If the mean deviation is 40°. What will be the angular dispersion produced by a prism of this material?
Prove that in case of a prism, i + e = A + δ, where the symbols have their usual meanings.
When a ray of white light is incident obliquely on the first surface of a prism, then ______.
