Advertisements
Advertisements
Question
Choose the correct option.
Angles of deviation for extreme colours are given for different prisms. Select the one having maximum dispersive power of its material.
Options
7°, 10°
8°, 11°
12°, 16°
10°, 14°
Advertisements
Solution
7°, 10°
Explanation:
Dispersive power for thin prism is,
ω = `(δ_"V"-δ_"R")/(((δ_"V"+δ_"R")/2)`
∴ For values in option (A),
ω = `(10-7)/(((10+7)/2))=6/17` = 0.35
For values in option (B),
ω = `(11-8)/(((11+8)/2))=6/19` = 0.31
For values in option (C),
ω = `(16-12)/(((16+12)/2))=2/7` = 0.28
For values in option (D),
ω = `(14-10)/(((14+10)/2))=1/3` = 0.33
Thus, value of ω is maximum for prism with angles of deviations, 7°, 10°.
APPEARS IN
RELATED QUESTIONS
State the conditions required for total internal reflection of light to take place
Name the factors affecting the critical angle for the pair of media.
State two conditions necessary for total internal reflection to occur.
Write the necessary conditions for the phenomenon of total internal reflection to
occur ?
Write the relation between the refractive index and critical angle for a given pair of optical media?
i) Observe the given figure and answer the following questions.
a) Identify and write the natural process shown in the figure.
b) List the phenomena which are observe in this process.
c) Redraw the diagram and show above phenomena in it.
The diagram below shows a light source P embedded in a rectangular glass block ABCD of critical angle 42°. Complete the path of the ray PQ till it emerges out of the block. [Write necessary angles].
Plot a graph between
Sine of angle of incidence versus sine of angle of refraction,
Plot a graph between
Angle of incidence versus angle of refraction.
Name the principle on the basis of which optical fibres work.
How does a ray of light bend when it travels from rarer to denser medium
How does a ray of light bend when it travels from when it is normal to the interface of the two media.
Express the refractive index μ of a medium in terms of the angle of incidence i in air and the angle of refraction r in a denser medium.
Name the factors affecting the critical angle for the pair of media.
What is meant by the term ‘critical angle’?
Draw a diagram, properly labelled, to illustrate the use of a total reflecting prism (a right-angled isosceles prism) to turn a ray of light through 180°. Name an instrument in which this device is used.
Describe the construction and working of an optical fibre.
Answer the following question.
Why is prism binoculars preferred over traditional binoculars? Describe its working in brief.
Solve Numerical example.
A monochromatic ray of light is incident at 37° on an equilateral prism of refractive index 3/2. Determine angle of emergence and angle of deviation. If angle of prism is adjustable, what should its value be for emergent rays to be just possible for the same angle of incidence?
For the same angle of incidence, the angle of refraction in four media A, B, C and D are 25°, 30°, 35° and 40° respectively. The speed of light is least in medium ______.
The angle of minimum deviation produced by a thin glass prism in air is 'δ'. If that prism is immersed in water, the angle of minimum deviation will be ______.
( aμg = refractive index of glass w.r.t, air aμw = refractive index of water w.r.t. air)
Which of the following statements about total internal reflection is true?
State the condition under which total internal reflection occurs. Give the mathematical expression for total internal reflection.
The diagram below shows a fish in the tank and its image seen on the surface of the water.
Name the phenomenon responsible for the formation of this image.
State two differences between normal reflection and total internal reflection.
