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Questions Available: 27
Year: 2025
Topic: Ray optics and optical instruments
1.
In a certain camera, a combination of four thin convex lenses are arranged axially in contact. Then the power of the combination and the total magnification in comparison to the power (p) and magnification (m) for each lens will be, respectively
(1).
\(\text{p}^4\) and \(\text{m}^4\)
(2).
\(4\text{p}\) and \(4\text{m}\)
(3).
\(\text{p}^4\) and \(4\text{m}\)
(4).
\(4\text{p}\) and \(\text{m}^4\)

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Solution
Year: 2018
Topic: Ray optics and optical instruments
2.
An object is placed at a distance of 40 cm from a concave mirror of focal length 15 cm. If the object is displaced through a distance of 20 cm towards the mirror, the displacement of the image will be
(1).
30 cm towards the mirror
(2).
36 cm away from the mirror
(3).
30 cm away from the mirror
(4).
36 cm towards the mirror

Test
Solution
Year: 2017
Topic: Ray optics and optical instruments
3.
A beam of light from a source L is incident normally on a plane mirror fixed at a certain distance x from the source. The beam is reflected back as a spot on a scale placed just above the source L. When the mirror is rotated through a small angle "q", the spot of the light is found to move through a distance y on the scale. The angle \(\theta\) is given by
(1).
\(\displaystyle \frac{\text{y}}{2\text{x}}\)
(2).
\(\displaystyle \frac{\text{y}}{\text{x}}\)
(3).
\(\displaystyle \frac{\text{x}}{2\text{y}}\)
(4).
\(\displaystyle \frac{\text{x}}{\text{y}}\)

Test
Solution
Year: 2016
Topic: Ray optics and optical instruments
4.
Match the corresponding entries of Column 1 with Column 2. [Where m is the magnification produced by the mirror]
(1).
A \(\rightarrow\) a and c; B \(\rightarrow\) a and d; C \(\rightarrow\) a and b; D \(\rightarrow\) c and d
(2).
A \(\rightarrow\) a and d; B \(\rightarrow\) b and c; C \(\rightarrow\) b and d; D \(\rightarrow\) b and c
(3).
A \(\rightarrow\) c and d; B \(\rightarrow\) b and d; C \(\rightarrow\) b and c; D \(\rightarrow\) a and d
(4).
A \(\rightarrow\) b and c; B \(\rightarrow\) b and c; C \(\rightarrow\) b and d; D \(\rightarrow\) a and d

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Solution
Year: 2025
Topic: Ray optics and optical instruments
5.
A microscope has an objective of focal length 2 cm, eyepiece of focal length 4 cm and the tube length of 40 cm. If the distance of distinct vision of eye is 25 cm, the magnification in microscope is
(1).
250
(2).
100
(3).
125
(4).
150

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Solution
Year: 2024
Topic: Ray optics and optical instruments
6.
A light ray enters through a right angled prism at point P with the angle of incidence \(30^ \circ\) as shown in figure . It travels through the prism parallel to its base BC and emerges along the face AC . The refractive index of the prism is :
(1).
\(\displaystyle \frac{\sqrt{3}}{4}\)
(2).
\(\displaystyle \frac{\sqrt{3}}{2}\)
(3).
\(\displaystyle \frac{\sqrt{5}}{4}\)
(4).
\(\displaystyle \frac{\sqrt{5}}{2}\)

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Solution
Year: 2024
Topic: Ray optics and optical instruments
7.
A small telescope has an objective of focal length 140 cm and an eye piece of focal length 5.0 cm . The magnifying power of telescope for viewing a distant object ?
(1).
17
(2).
32
(3).
34
(4).
28

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Solution
Year: 2023
Topic: Ray optics and optical instruments
8.
Light travels a distance x in time t1 in air and 10x in time t2 in another denser medium. What is the critical angle for this medium?
(1).
\(\displaystyle sin^{-1}\left(\frac{10t_2}{t_1}\right)\)
(2).
\(\displaystyle sin^{-1}\left(\frac{t_1}{10t_2}\right)\)
(3).
\(\displaystyle sin^{-1}\left(\frac{10t_1}{t_2}\right)\)
(4).
\(\displaystyle sin^{-1}\left(\frac{t_2}{t_1}\right)\)

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Solution
Year: 2023
Topic: Ray optics and optical instruments
9.
For Young's double slit experiment, two statements are given below:
Statement I : If screen is moved away from the plane of slits, angular separation of the fringes remains constant.
Statement II : If the monochromatic source is replaced by another monochromatic source of larger wavelength, the angular separation of fringes decreases.
In the light of the above statements, choose the correct answer from the options given below :
(1).
Both Statement I and Statement II are false
(2).
Statement I is true but Statement II is false
(3).
Statement I is false but Statement II is true
(4).
Both Statement I and Statement II are true

Test
Solution
Year: 2023
Topic: Ray optics and optical instruments
10.
In the figure shown here, what is the equivalent focal length of the combination of lenses (Assume that all layers are thin) ?
(1).
- 40 cm
(2).
- 100 cm
(3).
- 50 cm
(4).
40 cm

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Solution
Year: 2023
Topic: Ray optics and optical instruments
11.
Two thin lenses are of same focal lengths (F), but one is convex and the other one is concave. When they are placed in contact with each other, the equivalent focal length of the combination will be :
(1).
\(\displaystyle \frac{f}{4}\)
(2).
\(\displaystyle \frac{f}{2}\)
(3).
Infinite
(4).
Zero

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Solution
Year: 2022
Topic: Ray optics and optical instruments
12.
A light ray falls on a glass surface of refractive index \(\sqrt{3}\) , at an angle \(60^ \circ\) . The angle between the refracted and reflected rays would be :
(1).
\(30^\circ\)
(2).
\(60^\circ\)
(3).
\(90^\circ\)
(4).
\(120^\circ\)

Test
Solution
Year: 2022
Topic: Ray optics and optical instruments
13.
The transparent media A and B are separated by a plane boundary. The speed of light in those media are \(1.5 \times 10^ 8 \,m/s\) and \(2.0 \times 10^8 \,m/s\), respectively. The critical angle for a ray of light for these two media is :
(1).
\(sin^{–1}\left(0.500\right)\)
(2).
\(sin^{–1}\left(0.750\right)\)
(3).
\(tan^{–1}\left (0.500\right)\)
(4).
\(tan^{ –1}\left (0.750\right)\)

Test
Solution
Year: 2022
Topic: Ray optics and optical instruments
14.
A biconvex lens has radii of curvature, 20 cm each. If the refractive index of the material of the lens is 1.5, the power of the lens is
(1).
+2 D
(2).
+20 D
(3).
+5 D
(4).
Infinity

Test
Solution
Year: 2021
Topic: Ray optics and optical instruments
15.
Find the value of the angle of emergence from the prism. Refractive index of the glass is 3.
(1).
\(60^\circ\)
(2).
\(30^\circ\)
(3).
\(45^\circ\)
(4).
\(90^\circ\)

Test
Solution
Year: 2021
Topic: Ray optics and optical instruments
16.
A convex lens A of focal length 20 cm and a concave lens B of focal length 5 cm are kept along the same axis with a distance d between them. If a parallel beam of light falling on A leaves B as a parallel beam, then the distance d (in cm) will be
(1).
25
(2).
15
(3).
50
(4).
30

Test
Solution
Year: 2021
Topic: Ray optics and optical instruments
17.
A point object is placed at a distance of 60 cm from a convex lens of focal length 30 cm. If a plane mirror were put perpendicular to the principal axis of the lens and at a distance of 40 cm from it, the final image would be formed at a distance of
(1).
20 cm from the lens, it would be a real image
(2).
30 cm from the lens, it would be a real image
(3).
30 cm from the plane mirror, it would be a virtual image
(4).
20 cm from the plane mirror, it would be a virtual image

Test
Solution
Year: 2021
Topic: Ray optics and optical instruments
18.
A lens of large focal length and large aperture is best suited as an objective of an astronomical telescope, since
(1).
a large aperture contributes to the quality and visibility of the images
(2).
a large area of the objective ensures better light gathering power
(3).
a large aperture provides a better resolution
(4).
All of the above

Test
Solution
Year: 2020
Topic: Ray optics and optical instruments
19.
A ray is incident at an angle of incidence i on one surface of a small angle prism (with angle of prism A) and emerges normally from the opposite surface. If the refractive index of the material of the prism is \(\mu\), then the angle of incidence is nearly equal to
(1).
\(\displaystyle \frac{2\, \text{A}}{\mu}\)
(2).
\(\mu \text{A}\)
(3).
\(\displaystyle \frac{\mu \, \text{A}}{2}\)
(4).
\(\displaystyle \frac{\text{A}}{2\,\mu}\)

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Solution
Year: 2019
Topic: Ray optics and optical instruments
20.
Pick the wrong answer in the context with rainbow.
(1).
The order of colours is reversed in the secondary rainbow
(2).
An observer can see a rainbow when his front is towards the sun
(3).
Rainbow is a combined effect of dispersion refraction and reflection of sunlight
(4).
When the light rays undergo two internal reflections in a water drop,a secondary rainbow is formed

Test
Solution
Year: 2019
Topic: Ray optics and optical instruments
21.
Which colour of the light has thelongest wavelength?
(1).
Blue
(2).
Green
(3).
Violet
(4).
Red

Test
Solution
Year: 2019
Topic: Ray optics and optical instruments
22.
In total internal reflection when the angle of incidence is equal to the critical angle for the pair of media in contact, what will be angle of refraction?
(1).
\(0^\circ\)
(2).
Equal to angle of incidence
(3).
\(90^\circ\)
(4).
\(180^\circ\)

Test
Solution
Year: 2019
Topic: Ray optics and optical instruments
23.
Two similar thin equi-convex lenses, of focal length f each, are kept co-axially in contact with each other such that the focal length of the combination is F1 . When the space between the two lenses is filled with glycerine (which has the same refractive index (μ =1.5) as that of glass) then the equivalent focal length is F2 . The ratio F1 : F 2 will be
(1).
1 : 2
(2).
2 : 3
(3).
3 : 4
(4).
2 : 1

Test
Solution
Year: 2018
Topic: Ray optics and optical instruments
24.
The refractive index of the material of a prism is 2 and the angle of the prism is \(30^\circ\). One of the two refracting surfaces of the prism is made a mirror inwards, by silver coating. A beam of monochromatic light entering the prism from the other face will retrace its path (after reflection from the silvered surface) if its angle of incidence on the prism is
(1).
\(30^\circ\)
(2).
\(45^\circ\)
(3).
\(60^\circ\)
(4).
\(zero\)

Test
Solution
Year: 2017
Topic: Ray optics and optical instruments
25.
A thin prism having refracting angle \(10^\circ\) is made of glass of refractive index 1.42. This prism is combined with another thin prismof glass of refractive index 1.7. This combination produces dispersion without deviation. The refracting angle of second prism should be
(1).
\(4^\circ\)
(2).
\(6^\circ\)
(3).
\(8^\circ\)
(4).
\(10^\circ\)

Test
Solution
Year: 2016
Topic: Ray optics and optical instruments
26.
The angle of incidence for a ray of light at a refracting surface of a prismis \(45^\circ\). The angle of prism is \(60^\circ\). If the ray suffers minimum deviation through the prism, the angle of minimum deviation and refractive index of the material of the prism respectively, are
(1).
\(\displaystyle 30^\circ\, ; \sqrt{2}\)
(2).
\(\displaystyle 45^\circ\, ; \sqrt{2}\)
(3).
\(\displaystyle 30^\circ\, ; \frac{1}{\sqrt{2}}\)
(4).
\(\displaystyle 45^\circ\, ; \frac{1}{\sqrt{2}}\)

Test
Solution
Year: 2016
Topic: Ray optics and optical instruments
27.
A astronomical telescope has objective and eyepiece of focal lengths 40 cm and 4 cm respectively. To view an object 200 cmaway from the objective, the lenses must be separated by a distance
(1).
46.0 cm
(2).
50.0 cm
(3).
54.0 cm
(4).
37.3 cm

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Solution