a. 30° b. 60° c. 75° d. 90° Solution: A complete reflecting equilateral prism can be used to bend a light ray by 60 degrees.
A total reflecting equilateral prism can be used to deviate a ray of light through:
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Refraction of Light at Plane Surfaces
A total reflecting right-angled isosceles prism can be used to deviate a ray of light through
a. 30° b. 60° c. 75° d. 90° Solution: To deviate a ray of light through 90 degrees, use a complete reflecting right angled isosceles prism.
The critical angle for the glass-air interface is :
a. 24° b. 48° c. 42° d. 45° Solution: The correct option is (c) - 42 degrees
State one advantage of using a total reflecting prism as a reflector in place of a plane mirror.
Solution: The picture produced by a total reflecting prism is much brighter and the brightness remains constant even after extended use. But the image produced by a plane mirror is less brilliant...
Mention one difference between the reflection of light from a plane mirror and total internal reflection of light from a prism.
Solution: In total internal reflection of light from a prism, all of the incident light is reflected back into the denser medium. Whereas in conventional reflection from a plane mirror, only a...
Two isosceles right-angled glass prisms P and Q are placed near each other as shown in Fig. Complete the path of the light ray entering the first prism till it emerges out of the second prism Q.
Solution :
Draw a neat labelled ray diagram to show the total internal reflection of a ray of light normally incident on one face of a 30°, 90°, 60° prism.
Solution:
In Fig., a ray of light PQ is incident normally on the face AB of an equilateral glass prism. Complete the ray diagram showing its emergence into air after passing through the prism.
Take critical angle for glass = 42° (a)Write the angles of incidence at the faces AB and AC of the prism. (b)Name the phenomenon which the ray of light suffers at the face AB, AC and BC of the...
In Fig., a ray of light PQ is incident normally on the hypotenuse of an isosceles right angle prism ABC.
(a) Complete the path of the ray PQ until it emerges from the prism. Mark in the diagram the angle wherever necessary. (b) What is the angle of deviation of the ray PQ? (c) Name a device in which...
A ray of light OP passes through a right-angled prism as shown in the adjacent diagram.
(a)State the angles of incidence at the faces AC and BC. (b)Name the phenomenon which the ray suffers at the face AC. Solution: (a) The incidence angle at the face AC is 45 degrees, while the...
Show with the help of a diagram how a total reflecting prism can be used to turn a ray of light through 90°. Name one instrument in which such a prism is used.
Solution: A beam of light is incident normally at the face AB in the illustration above. As a result, it passes through the prism undeviated and strikes the face AC at a 45-degree angle of...
What is a total reflecting prism? State three actions that it can produce. Draw a diagram to show one action of the total reflecting prism.
Solution: A fully reflecting prism is described as a prism with an angle of 900 between its two refracting surfaces and two additional angles of 450 each. When light is incident ordinarily on any of...
A ray of light enters a glass ABCD as shown in Fig. and strikes at the Centre O of the circular part AC of the slab. The critical angle of glass is 42°. Complete the path of the ray till it emerges out from the slab. Mark the angles in the diagram wherever necessary.
Solution : At its crucial angle, the beam strikes the glass. As a result, the refraction angle will be 90 degrees.
The refractive index of glass is 1.5. From a point P inside a glass block, draw rays PA, PB and PC incident on that glass-air surface at an angle of 30o, 42o and 60o respectively.
(a)In the diagram show the approximate direction of these rays as they emerge out of the block. (b)What is the angle of refraction for the ray PB? Solution: (a) According to the question, refractive...
In the figure, PQ and PR are the two light rays emerging from an object P. The ray PQ is refracted as QS.
(a) State the special name given to the angle of incidence ∠PQN of the ray PQ. (b) What is the angle of refraction for the refracted ray QS? (c)Name the phenomenon that occurs if the angle of...
Fig. shows a point source P inside a water container. Three rays A, B and C starting from the source P are shown up to the water surface.
(a) Show in the diagram, the path of these rays after striking the water surface. The critical angle for water-air surface is 48°. (b) Name the phenomenon which the rays A, B and C exhibit. Solution...
Figure below show two rays A and B travelling from water to air. If the critical angle for water- air surface is 48°, complete the ray diagram showing the refracted rays for each. State conditions when the ray will suffer total internal reflection.
Solution ; There are two prerequisites for total introspective reflection: (i) Light must pass through a denser media before reaching a rarer medium. (ii) The incidence angle must be larger than or...
The refractive index of air with respect to glass is expressed as gμa = sin i / sin r
(a) Write down a similar expression for aμg in terms of angle i and r. (b) If angle r = 900, what is the corresponding angle i called? (c) What is the physical significance of the angle i and part...
State whether the following statement is true or false:
If the angle of incidence is greater than the critical angle, light is not refracted at all, when it falls on the surface from a denser medium to a rarer medium. Solution: This statement is true....
Fill in the blanks to complete the following sentences:
(a) When a ray of light moves from a denser media to a rarer medium, _____________ happens. (b) The ____________ is the angle of incidence in a denser medium for which the refraction angle in a...
(a)What is total internal reflection?
(b)State two conditions necessary for total internal reflection to occur. (c)Draw diagrams to illustrate critical angle and total internal reflection. Solution: (a) Total internal reflection: A beam...
The critical angle for glass-air is 45° for the light of yellow colour. State whether it will be less than, equal to, or more than 45° for (i) red light, (ii) blue light?
Solution: The refractive index increases (or drops) when the wavelength of light decreases (or increases), and the critical angle decreases (or more) (i) The crucial angle for red light will be more...
Name two factors which affect the critical angle for a given pair of media. State how do the factors affect it.
Solution: The crucial angle is influenced by two factors. (a) The wavelength or colour of light, and (b) The ambient temperature Effect on light colour: For a pair of media, the critical angle is...
A light ray is incident from a denser medium on the boundary separating it from a rarer medium at an angle of incidence equal to the critical angle. What is the angle of refraction for the ray?
Solution: When a beam is incident from a denser media to a rarer medium at an angle of incidence equal to the critical angle, the angle of refraction becomes 90 degrees.
What is the meant by the statement ‘the critical angle for diamond is 24°?
Solution: The phrase "the critical angle for diamond is 24° suggests that at a 24° incidence angle, the angle of refraction in the air will reach 90° within the diamond. When the incidence angle...
State the approximate value of the critical angle for
(a) glass-air surface (b) water-air surface. Solution: (a) According to the question, refractive index aμg = 3 / 2 Therefore, critical angle for glass – air surface is given by - sin...
How is the critical angle related to the refractive index of a medium?
Solution: The relationship between critical angle and a medium's refractive index is known as the critical angle-refractive-index relationship. μ = 1 / sin C = cosec C
Explain the term critical angle with the aid of a labelled diagram.
Solution: The critical angle is the angle of incidence in the denser medium that corresponds to the angle of refraction in the rarer media of 90 degrees.
A postage stamp kept below a rectangular glass block or refractive index 1.5 when viewed from vertically above it, appears to be raised by 7.0 mm. Calculate the thickness of the glass block.
Solution: According to the question, refractive index of the glass block (μg) is 1.5 and the shift in the image is 7 mm or 0.7 cm We have to determine the thickness of glass block or real depth...
A coin is placed at the bottom of a beaker containing water (refractive index = 4/3) to a depth of 12 cm. By what height the coin appears to be raised when seen from vertically above?
Solution: According to the question, refractive index of the water (μw) is 4 / 3 and the real depth of coin is 12 cm We have to find the shift in the image Expression for the shift in image in terms...
A water pond appears to be 2.7 m deep. If the refractive index of water is 4/3, find the actual depth of the pond.
Solution: According to the question, apparent depth is 2.7 m and the refractive index of water (μw) is 4 / 3 Therefore, using the expression of refractive index we can write => Real depth = Apparent...
An object in a denser medium when viewed from a rarer medium appears to be raised. The shift is maximum for:
a. Red light b. Violet light c. Yellow light d. Greenlight Solution: The correct option is (b) - violet light. The shift is greatest for violet light because violet light has the...
A small air bubble in a glass block when seen from above appears to be raised because of:
a. Refraction of light b. Reflection of light c. Reflection and refraction of light d. None of the above Solution: The correct option is (a). A spherical air bubble in glass...
An object placed in one medium when seen from the other medium, appears to be vertically shifted. Name the factors on which the magnitude of shift depends and state how does it depend on them.
Solution: The apparent elevation of the item is determined by: (i) The medium's refractive index. (ii) The denser medium's thickness and (iii) The wavelength or colour of incoming light The shift...
A student puts his pencil into an empty trough and observes the pencil from the position as indicated in the Fig.
(i) What change will be observed in the appearance of the pencil when water is poured into the trough? (ii) Name the phenomenon which accounts for the above-started observation....
A fish is looking at a 1.0 m high plant at the edge of the pond. Will the plant appear shorter or taller than its actual height? Draw a ray diagram to support your answer.
Solution: The plant will appear to be taller than its real height. Allow the fish to gaze from point O. Because air is a rarer material than water, when the ray OP comes from the water into air, it...
Draw a ray diagram to show the appearance of a stick partially immersed in water. Explain your answer.
Solution: A stick appears bent or lifted in the above image, which is partially immersed in water in a glass container. This is because the rays appear to be coming from P', which is a virtual image...
Water in a pond appears to be only three-quarters of its actual depth. (a) What property of light is responsible for this observation? Illustrate your answer with the help of a ray diagram. (b) How is the refractive index of water calculated from its real and apparent depths?
Solutions: (a) This observation is due to refraction of light. Light is bent away from the normal due to refraction from a denser media to a rarer medium. (b) Assume that an object B is located at...
A tank of water is viewed normally from above.
(a) State how the depth of tank appears to change. (b) Draw a labelled ray diagram to explain your answer. Solution: (a) The depth of the tank seems to be less than its true depth due to light...
Prove that
Refractive index = Real depth / Apparent depth Solution: Take a look at a ray of light. OA is generally incident on the surface PQ. It follows AA' in a straight line. Consider another beam from O...
How is the refractive index of a medium related to the real and apparent depths of an object in that medium?
Solution: The refractive index μ is related to the real and apparent depths in the following manner - μ = Real Depth / Apparent Depth
What should be the angle of incidence for a ray of light which suffers a minimum deviation of 36o through an equilateral prism?
Solution: According to the question, the angle of prism is A = 600 And the angle of minimum deviation is ????min = 360 We have to find the angle of incidence, i Expression of minimum deviation is...
A ray of light incident at an angle 48o on a prism of refracting angle 60o suffers minimum deviation. Calculate the angle of minimum deviation.
Solution: According to the question, the angle of incidence is i = 480 And the angle of refraction is A = 600 We have to determine the angle of minimum deviation, ????min Expression of the angle of...
A ray of light suffers refraction through an equilateral prism. The deviation produced by the prism does not depend on the:
(a) angle of incidence (b) colour of light (c) material of prism (d) size of prism Solution: The correct option is (d). The deviation of a prism is determined by:Prism refractive index- The...
In refraction of light through a prism, the light ray:
a. Suffers refraction only at one face of the prism b. Emerges out from the prism in a direction parallel to the incident ray c. Bends at both the surfaces of prism towards its base...
The diagram below shows two identical prisms A and B placed with their faces parallel to each other. A ray of light of single colour PQ is incident at the face of the prism A. Complete the diagram to show the path of the ray till it emerges out of the prism B
Solution :
A ray of light is normally incident on one face of an equilateral glass prism. Answer the following
(a)What is the angle of incidence on the first face of the prism? (b)What is the angle of refraction from the first face of the prism? (c)What will be the angle of incidence at the second face of...
An object is viewed through a glass prism with its vertex pointing upwards. Draw a ray diagram to show the formation of its image seen by the observer.
Solution: Allow two rays OA and OL from a light source O to collide with the prism. They are refracted along AB and LM, respectively, from the prism's first face. These two rays refract off the...
How does the angle of deviation depend on refracting angle of the prism?
Solution: The angle of deviation (????) grows as the angle of prism (A) increases.
Which of the two prisms, A made of crown glass and B made of flint glass, deviate a ray of light more?
Solution: The refractive index of the B constructed of flint glass is greater. As a result, B constructed of flint glass deviates a light beam more.
Name the colour of white light which is deviated (i) the most, (ii) the least, on passing through a prism.
Solution: Violet colours diverge the greatest when passing through a prism, whereas red colours stray the least.
A light ray of yellow colour is incident on an equilateral glass prism at an angle of incidence equal to 48o and suffers minimum deviation by an angle of 36o. (i) What will be the angle of emergence? (ii) If the angle of incidence is changed to (a) 30o, (b) 60o, state whether the angle of deviation will be equal to less than or more than 36o.
Solution: (i) We know that the ray suffers minimum deviation in an equilateral prism. So we can write i1 = i2 Therefore, i2 = 480 (ii) (a) If the incidence angle is increased to 30 degrees ,...
Draw a ray diagram to show the refraction of a monochromatic ray through a prism when it suffers minimum deviation. How is the angle of emergence related to the angle of incidence in this position.
Solution: In the equilateral prism, the angle of incidence i1 is equal to the angle of emergence i2 when the prism is in minimum deviation. Therefore, i1 = i2 = i
A ray of light incident at an angle of incidence i1 passes through an equilateral glass prism such that the refracted ray inside the prism is parallel to its base and emerges at an angle of emergence i2.
(a) How is the angle of emergence ‘i2‘ related to the angle of incidence ‘i1‘. (b) What can you say about the angle of deviation in such a situation? Solution: (i) The relation between the angle of...
Write a relation for the angle of deviation (????) for a ray of light passing through an equilateral prism in terms of angle of incident (i), angle of emergence (e), angle of prism (A).
Solution: For a beam of light travelling through an equilateral prism, the angle of incidence (i) angle of emergence (e), angle of prism (A), and angle of deviation ( ???? ) are related as follows:...
How does the angle of minimum deviation produced by a prism change with increase in (i) the wavelength of incident light and (ii) the refracting angle of the prism?
Solution: I The angle of deviation decreases as the wavelength of incident light increases. (ii) As the refracting angle of the prism increases, so does the angle of deviation.
How does the deviation produced by a prism depend on
(i) the refraction index of its material, and (ii) the wavelength of incident light Solution: (i) For a given angle of incidence, a prism with a higher refractive index produces a bigger...
State whether the following statement is ‘true’ or ‘false’.
The deviation produced by a prism is independent of the angle of incidence and is same for all the colors of light. Solution: False. The angle of deviation decreases at initially, then increases as...
a) How does the angle of deviation produced by a prism change with increase in the angle of incidence. Draw a curve showing the variation in the angle of deviation with the angle of incidence at a prism surface.
(b) Using the curve in part (a) above, how do you infer that for a given prism, the angle of minimum deviation δmin is unique for the given light. Solution: Dependence of angle of deviation...
What do you understand by the deviation produced by a prism? Why is it caused? State three factors on which angle of deviation depends.
Solution: The ray of light in a prism is refracted by two sloped sides. The prism causes one deviation on the first surface and another on the second surface. As a result, a prism causes a deviation...
Complete the following sentence:
The angle of deviation is the angle formed by the ____________ with the direction of ___________. Solution: The angle of deviation is the angle formed by the emergent ray with the direction of...
Define the term angle of deviation.
Solution: The angle of deviation is the angle formed by the incident ray's direction and the emergent ray's direction.
The diagrams (a) and (b) in Fig. below show the refractions of a ray of light of single colour through a prism and a parallel-sided glass and prism, respectively.
(a) In each diagram, label the incident, refracted, emergent rays and the angle of deviation. (b) In what way the direction of emergent ray in the two cases differ with respect to the incident...
With the help of a diagram of a prism, indicate its refracting surfaces, refracting angle and base.
Solution: A prism is a transparent material with a triangular cross section surrounded by five plane surfaces.
A ray of light of wavelength 5400 Angstrom suffers refraction from air to glass. Taking aμg = 3/2, find the wavelength of light in glass.
Given, According to the question, wavelength of light in air is 5400 A0 And the refractive index of glass with respect to air is, aμg = 3 / 2 where a is for air and g is for glass So, using the...
The refractive index of water with respect to air is 4/3. What is the refractive index of air with respect to water?
Solution: According to the question, the refractive index of water with respect to air is air μwater = 4 / 3 We can easily determine the refractive index of air with respect to water in the...
The speed of light in diamond is 125,000 km s-1. What is the refractive index? (speed of light in air = 3 x 108 m s-1).
Solution: Given, According to the question, speed of light in diamond is = 125,000 km s-1 Or, = 125 × 106 m / s We know that the speed of light in air is c = 3 × 108 m / s We have to find the...
The speed of light in air is 3 x 108 m s-1. Calculate the speed of light in glass. The refractive index of glass is 1.5.
Solution: Given According to the question, speed of light in air is c = 3 × 108 m / s And the refractive index of glass is μ = 1.5 We have to calculate the speed of light in glass, v Using the...
The highest refractive index is of:
a. Glass b. Water c. Diamond d. Ruby Solution: The correct option is (c) - Diamond. Diamond has the greatest refractive index, with a value of 2.42.Glass has a refractive index...
How does the refractive index of a medium depend on its temperature?
Solution: The refractive index of a medium drops as the temperature of the medium rises. With a rise in temperature, the speed of light in that medium increases. As a result, the refractive index =...
A light ray does not bend at the boundary in passing from one medium to the other medium if the angle of incidence is:
a. 0° b. 45° c. 60° d. 90° Solution: The correct option is (a) - 0 degrees. The angle of incidence is the angle formed by a light ray and a surface normal. If...
When a ray of light from air enters a denser medium, it:
a. Bends away from the normal b. Bends towards the normal c. Goes undeviated d. Is reflected back Solution: The correct option is (b). The ray of light bends towards the...
Fill in the blanks to complete the following sentences:
(a) The speed of light ___________ when it passes from a rarer to a denser material. (b) The speed of light ___________ when it travels from a denser to a rarer medium. (c) Glass has a refractive...
When an illuminated object is held in front of a thick plane glass mirror, several images are seen, out of which the second image is the brightest. Give reason.
Solution: When a ray of light from a lit candle lands on the surface of the mirror, a small portion of the light (almost 4% ) is reflected. It generates a weak virtual picture, while the majority of...
A ray of green light enters a liquid from air, as shown in the figure. The angle 1 is 45 degrees and angle 2 is 30 degrees.
a) Find the refractive index of liquid.(b) Show in the diagram the path of the ray after it strikes the mirror and re-enters in air. Mark in the diagram the angles wherever necessary.(c) Redraw the...
In the adjacent diagram, AO is a ray of light incident on a rectangular glass slab.
(a) Complete the path of the ray until it emerges out of the slab. (b) In the ray diagram, mark the angle of incidence (i) and the angle of refraction (r) at the first interface. How...
A ray of light strikes the surface at a rectangular glass slab such that the angle of incidence is (i) 0o, (ii) 45o. In each case, draw a diagram to show the path taken by the ray as it passes through the glass slab and emerges from it.
Solution: (i) In case, the angle of incidence is equal to 00 (ii) When the angle of incidence is 450
What is lateral displacement? Draw a ray diagram showing the lateral displacement of a ray of light when it passes through a parallel-sided glass slab.
Solution: The lateral displacement is defined as the perpendicular distance between the emergent ray's route and the incident ray's direction. In the diagram above, XY represents the perpendicular...
The refractive index of water with respect to air is aμw and of glass with respect to air is aμg. Express the refractive index of glass with respect to water.
Solution: The refractive index of the glass with respect to the water is given as follows - w μg = aμg / aμw
The diagram alongside shows the refraction of a ray of light from air to liquid.
(a) Write the values of (i) angle of incidence, and (ii) angle of refraction. (b) Use Snell’s law to find the refractive index of liquid with respect to air. (a) (i) The angle of incidence...
In the figure below, a ray of light A incident from air suffers partial reflection and refraction at the boundary of water.
(a) Complete the diagram showing (i) the reflected ray B and (ii) the refracted ray C. (b) How are the angles of incidence i and refraction r related? Solution: The angle of incidence and...
How does the refractive index of a medium depend on its temperature?
Solution: The refractive index of a medium drops as the temperature of the medium rises. With a rise in temperature, the speed of light in that medium increases. As a result, the refractive index =...
How does the refractive index of a medium depend on the wavelength of light used?
Solution: The refractive index of a medium drops as the wavelength of light increases. Violet light, which has the shortest wavelength, has a higher refractive index than red light, which has the...
Name two factors on which the refractive index of a medium depends? State how does it depends on the factor state by you.
Solution: The following are the elements that influence a medium's refractive index: (i) Medium nature (e.g. μg = 1.5, μw = 1.33): The lower the speed of light in the medium compared to air, the...
(a)For which colour of white light, is the refractive index of a transparent medium (i) the least (ii) the most?
(b) Which colour of light travels fastest in any medium except air? Solution: (a) (i) Red has the lowest refractive index of any transparent medium. (ii) Violet colour has the highest refractive...
In an experiment of finding the refractive index of glass, if blue light is replaced by the red light, how will the refractive index of the glass change? Give reason in support of your answer.
Solution: The speed of red light in glass is faster than that of blue light. c / v is the refractive index. As a result, the refractive index of glass for red light will be lower than that for blue...
A monochromatic ray of light passes from air to glass. The wavelength of light in air is λ, the speed of light in air is c and in glass is v. If the refractive index of glass is 1.5, write down (a) the relationship between c and v, (b) the wavelength of light in the glass.
Solution: (a) Expression of the relation between the speed of light (c) in the air and in glass (v) is as follows - μ = c / v or we can write c = 1.5 v (b) Let the wavelength of light in glass be...
What do you understand by the statement ‘the refractive index of the glass is 1.5 for white light’?
Solution: White light travels 1.5 times faster in air than through glass, according to this assertion.
A light ray in passing from water to a medium (a) speeds up (b) slows down. In each case, (i) give one example of the medium, (ii) State whether the refractive index of a medium is equal to, less than or greater than the refractive index of water.
Solution: (a) When a light ray travels from water to air, it accelerates. (b) A light ray slows down as it travels from water to a glass medium. (c) It means that when the speed increases, the...
A light ray passes from water to (i) air, and (ii) glass. In each case, state how does the speed of light change?
Solution: Water has a refractive index of 1.33. Air has a refractive index of 1.0003. Glass has a refractive index of 1.5. This shows that μa < μw < μg When light travels from a rarer to a...
(a) Compare the speeds of light of wavelength 4000 Angstrom (i.e. violet light) and 8000 Angstrom (i.e. red light) in vacuum.
Solution: (a) Because the speed of light is determined by the medium rather than the wavelength, the speed will be the same for both. (b) Because a denser medium has a greater refractive index, the...
Define the term refractive index of a medium. Can it be less than 1?
Solution: The ratio of the sine of the angle of incidence in the first medium to the sine of the angle of refraction in the second medium is the refractive index of the second medium with respect to...
State the Snell’s laws of refraction of light.
Solution: Snell's laws of light refraction are a set of rules that govern how light bends. (i) At the point of incidence, the incident ray, the refracted ray, and the normal are all in the same...
A ray of light passes from medium 1 to medium 2. Which of the following quantities of the refracted ray will differ from that of incident ray: speed, intensity, frequency and wavelength?
Solution: The refracted ray's speed, intensity, and wavelength will differ from the incident ray in these three dimensions.
A light ray suffers reflection and refraction at the boundary in passing from air to water. Draw a neat labelled diagram to show it.
Solution: Air is a rarer medium than water. Water has a refractive index of 1.33 and is denser. As a result, a ray of light that goes from air to water (i.e. from rarer to denser) bends towards the...
What is the cause of refraction of light when it passes from one medium to another?
Solution: Because light travels at various speeds in different media, it can change the direction of its course in another material. Or induce refraction at times. Because of the shift in light...
An obliquely incident light ray bends at the surface due to change in speed, when passing from one medium to other. The ray does not bend when it is incident normally. Will the ray have different speed in the other medium?
Solution: Yes, the ray moves at a different pace in the other medium because the speed of light changes as the medium changes.
A ray of light is incident normally on a plane glass slab. What will be (i) the angle of refraction and (ii) the angle of deviation for the ray?
Solution: Because the angle of incidence is 0 degrees, a ray of light incident on a plane glass slab passes without any deviation, meaning it does not bend at the surface. As a result, if the angle...
Draw diagrams to show the refraction of light from (i) air to glass, (ii) glass to air. In each diagram, label the incident ray, refracted ray, the angle of incidence (i) and the angle of refraction (r).
Solution: (i) Diagram of Refraction of light from air to glass (ii) Diagram of Refraction of light from glass to air
What do you understand by the refraction of light?
Solution: Refraction of light is the change in direction of the path of light as it passes through one transparent media and into another transparent medium.