Ray Optics PYQs Set 3 (PDF)

Set 3 of 16 · Questions 61-90 of 467

In the print window choose “Save as PDF”. The file prints without a web address or date line.

Mere Teacher · Previous Year Questions NEET Physics · Ray Optics · Set 3 (Q61-90)
Scan or visit mereteacher.com for free PYQ practice, timed CBT tests, step-by-step solutions and BroBot AI. Answers and solutions are free with a sign-up.
61. $If the refractive index of the material of a prism is , where is the angle of prism then the angle of minimum deviation will be$ (1) $π - 2 A$ (2) $\frac{π}{2} - 2 A$ (3) $π - A$ (4) $\frac{π}{2} - A$ 62. $A man who cannot see clearly beyond 5 m wants to see stars clearly. He should use a lens of focal length$ (1) $- 100 m$ (2) $+ 5 m$ (3) $- 5 m$ (4) $Very large$ 63. $Two transparent media A and B are separated by a plane boundary. The speed of light in those media are 1.5 \times 10^{8} m / s and 2.0 \times 10^{8} m / s, respectively. The critical angle for a ray of light for these two media is [NEET 2022]$ (1) $sin^{- 1} (0.750)$ (2) $tan^{- 1} (0.500)$ (3) $tan^{- 1} (0.750)$ (4) $sin^{- 1} (0.500)$ 64. $Surface of certain metal is first illuminated with light of wavelength λ_{1} = 350 nm and then, by light of wavelength λ_{2} = 540 nm It is found that the maximum speed of the photo electrons in the two cases differ by a factor of (2) The work function of the metal (in eV) is close to: (Energy of photon n = \frac{1240}{λ ( in nm )} eV)$ (1) $1.8$ (2) $2.5$ (3) $5.6$ (4) $1.4$ 65. $A plano convex lens of refractive index and focal length is kept in contact with another plano concave lens of refractive index and focal length If the radius of curvature of their spherical faces is each and then and are related as:$ (1) $μ_{1} + μ_{2} = 3$ (2) $2 μ_{1} - μ_{2} = 1$ (3) $3 μ_{2} - 2 μ_{1} = 1$ (4) $2 μ_{2} - μ_{1} = 1$ 66. $Given below are two statements :Statement I : When the white light passed through a prism, the red light bends lesser than yellow and violet.Statement II : The refractive indices are different for different wavelengths in dispersive medium. In the light of the above statements, chose the correct answer from the options given below:$ (1) $Statement I is false but Statement II is true$ (2) $Statement I is true but Statement II is false$ (3) $Both Statement I and Statement II are true$ (4) $Both Statement I and Statement II are false$ 67. $The image formed by a convex mirror of focal length 30 cm is a quarter of the size of the object. The distance of the object from the mirror is$ (1) $30 cm$ (2) $90 cm$ (3) $120 cm$ (4) $60 cm$ 68. $A ray is incident from a medium of refractive index 2 into a medium of refractive index 1 . The critical angle is$ (1) $30^{\circ}$ (2) $60^{\circ}$ (3) $45^{\circ}$ (4) $90^{\circ}$ 69. $An object is placed at a distance of 40 cm in front of a concave mirror of focal length 20 cm . The image produced is$ (1) $real, inverted and smaller in size$ (2) $real, inverted and of same size$ (3) $real and erect$ (4) $virtual and inverted$ 70. $Ratio of intensities of two waves are given by4: 1. nen ratio of the amplitudes of the two waves is$ (1) $2: 1$ (2) $1 : 2$ (3) $4: 1$ (4) $1 : 4.$ 71. $There is a small source of light at some depth below the surface of water (refractive index ) in a tank of large cross sectional surface area. Neglecting any reflection from the bottom and absorption by water, percentage of light that emerges out of surface is (nearly):[Use the fact that surface area of a spherical cap of height and radius of curvature is ]$ (1) $50 %$ (2) $34 %$ (3) $17 %$ (4) $21 %$ 72. $The angle of deviation produced by a thin prism when placed in air is ' ' and that when immersed in water is ' . The refractive index of glass and water are and respectively. The ratio is$ (1) $1 : 2$ (2) $2 : 1$ (3) $1 : 4$ (4) $4 : 1$ 73. $A light ray travels from a medium with refractive index to another medium of refractive index . If and , then find the critical angle.$ (1) $15^{\circ}$ (2) $30^{\circ}$ (3) $45^{\circ}$ (4) $60^{\circ}$ 74. $In parallax method for the determination of focal length of a concave mirror, the object should always be placed:$ (1) $between the focus (F) and the centre of curvature (C) of the mirror ONLY$ (2) $between the pole(P) and the focus (F) of the concave mirror ONLY$ (3) $beyond the centre of the curvature (C) of the mirror ONLY$ (4) $at any point beyond the focus (F) of the mirror$ 75. $Light travels through a glass plate of thickness and having a refractive index If is the velocity of light in vacuum, the time taken by light to travel this thickness of glass is$ (1) $\frac{t}{μ c}$ (2) $\frac{μ t}{c}$ (3) $t μ c$ (4) $\frac{t c}{μ} .$ 76. $A ray of light passes through an equilateral glass prism in such a mamner that the angle of incidence is equal to the angle of emergence and each of these angles is equal to \frac{3}{4} of the angle of the prism. The angle of deviation is$ (1) $20^{\circ}$ (2) $45^{\circ}$ (3) $30^{\circ}$ (4) $39^{\circ}$ 77. $A focal length of a lens is 10 cm . What is power of a lens in dioptre?$ (1) $15 D$ (2) $0.1 D$ (3) $20 D$ (4) $10 D$ 78. $A ray of light travelling in a transparent medium of refractive index , falls on a surface separating the medium from air at an angle of incidence of . For which of the following value of , the ray can undergo total internal reflection?$ (1) $μ = 1.33$ (2) $μ = 1.40$ (3) $μ = 1.50$ (4) $μ = 1.25$ 79. $Two beams of red and violet colours are made to pass separately through a prism of . In the minimum deviation position, the angle of refraction inside the prism will be$ (1) $greater for red colour$ (2) $equal but not 30^{\circ} for both the colours$ (3) $greater for violet colour$ (4) $30^{\circ} for both the colours.$ 80. $The frequency of a light ray is . Its frequency when it propagates in a medium of refractive index 1.5, will be$ (1) $1.67 \times 10^{14} Hz$ (2) $9.10 \times 10^{14} Hz$ (3) $6 \times 10^{14} Hz$ (4) $4 \times 10^{14} Hz$ 81. $A beam of light from a source L is incident normally on a plane mirror fixed at a certain distance x from the source. The beam is reflected back as a spot on a scale placed just above the source L. When the mirror is rotated through a small angle θ, the spot of the light is found to move through a distance y on the scale. The angle θ is given by [NEET 2017]$ (1) $\frac{y}{2 x}$ (2) $\frac{y}{x}$ (3) $\frac{x}{2 y}$ (4) $\frac{x}{y}$ 82. $Radii of curvature of a converging lens are in the ratio . Its focal length is and refractive index is 1.5 . Then its radii of curvature are respectively.$ (1) $9 cm and 18 cm$ (2) $6 cm and 12 cm$ (3) $3 cm and 6 cm$ (4) $4.5 cm and 9 cm$ 83. $Calculate the focal length of a reading glass of a person if his distance of distinct vision is 75 cm .$ (1) $37.5 cm$ (2) $100.4 cm$ (3) $25.6 cm$ (4) $75.2 cm$ 84. $The focal lengths of the objective and the eyepiece of a compound microscope are 2 cm and 3 cm respectively and the distance between them is 15 cm . The final image formed by the eyepiece is at infinity. The distances of the object and the image produced by the object from the objective lens are respectively ,$ (1) $2.4 cm, 12 cm$ (2) $2.4 cm, 15 cm$ (3) $2.3 cm, 12 cm$ (4) $2.3 cm, 3 cm$ 85. $Light travels a distance x in time t_{1} in air and 10x in time t_{2} in another denser medium. What is the critical angle for this medium? [NEET 2023]$ (1) $sin^{- 1} (\frac{10 t _{2}}{t _{1}})$ (2) $sin^{- 1} (\frac{t _{1}}{10 t _{2}})$ (3) $sin^{- 1} (\frac{10 t _{1}}{t _{2}})$ (4) $sin^{- 1} (\frac{t _{2}}{t _{1}})$ 86. $According to Cartesian sign convention, in ray optics$ (1) $all distances in the direction of incident ray are taken positive.$ (2) $all distances are taken negative$ (3) $all distances in the direction of incident ray are taken negative$ (4) $all distances are taken positive.$ 87. $A convex lens made of glass (refractive index ) has focal length 24 cm in air. When itis totally immersed in water (refractive index ), its focal length changes to$ (1) $24 cm$ (2) $96 cm$ (3) $48 cm$ (4) $72 cm$ 88. $A plane glass plate is placed over a various coloured letters (violet, green, yellow, red). The letter which appears to raised more is$ (1) $Red$ (2) $Yellow$ (3) $Green$ (4) $Violet$ 89. $Consider a light source placed at a distance of 1.5 m along the axis facing the convex side of a spherical mirror of radius of curvature 1 m . The position (s^{’}, nature and magnification (m) of the image are$ (1) $s^{’} = 0.375 m, virtual, upright, m=0.25$ (2) $s^{’} = 0.375 m, real, inverted, m=0.25$ (3) $s^{’} = 3.75 m, virtual, inverted, m=2.5$ (4) $s^{’} = 3.75 m, real, upright, m=2.5$ 90. $If the refractive index from air to glass is and that from air to water is , then the ratio of focal lengths of a glass lens in water and in air is$ (1) $1 : 2$ (2) $2 : 1$ (3) $1 : 4$ (4) $4 : 1$