Ray Optics & Optical Instruments — practice questions

166 curated practice questions from Ray Optics & Optical Instruments (Physics Class 12, CBSE) — 119 easy, 31 medium, 16 hard. Every question includes the final answer free; step-by-step worked solutions with a free account.

• A double convex lens made of glass of refractive index 1.56 has both radii of curvature of magnitude 20 cm. If an…
• A ray of light incident at an angle i on a refracting face of a prism emerges from the other face normally. If the…
• For a concave mirror of focal length f , the minimum distance between the object and its real image is:
• A thin convex lens of focal length 25 cm is cut into two pieces 0.5 cm above the principal axis. The top part is placed…
• Two lenses of power +10 D and –5 D are placed in contact. Where should an object be held from the lens, so as to obtain…
• A ray is incident at an angle of incidence i on one surface of a prism of small angle A and emerges normally from…
• A beam of monochromatic light is refracted from vacuum into a medium of refractive index 1 5 . The wavelength of…
• A point object is kept 60 cm in front of a spherical convex surface ( n =1.5 , radius of curvature 40 cm). The image…
• The human eye has an approximate angular resolution of φ = 5.8 × 10 –4 rad and typical photoprinter prints a minimum of…
• A small angle prism (μ = 1.62) gives a deviation of 4.8°. The angle of prism is
• The image of the needle placed 45 cm from a lens is formed on a screen placed 90 cm on the other side of the lens. The…
• A ray of light is incident at 60° on one face of a prism of angle 30° and the emergent ray makes 30° with the incident…
• A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal…
• Assertion (A): The magnifying power of a compound microscope is negative. Reason (R): The final image formed is erect…
• A tub is filled with a transparent liquid to a height of 30.0 cm. The apparent depth of a coin lying at the bottom of…
• The distance of distinct vision of a person is 50 cm. He wants to read a book placed at 25 cm. What should be the focal…
• Which of the following pairs of media has the least value of critical angle?
• Which of the following colours of white light deviated most when passes through a prism?
• A beaker is filled with water(refractive index 4 3 ) upto a height H. A coin is placed at its bottom. The depth of the…
• You are given four sources of light each one providing a light of a single colour – red, blue, green and yellow…
• The speed of light in two media '1' and '2' are v_ 1 and v_ 2 ( v_ 1 ) respectively. For a ray of light to undergo…
• A screen is placed 90 cm away from an object. The image of the object on the screen is formed by a convex lens at two…
• The focal length of the lenses of an astronomical telescope are 50 cm and 5 cm. The length of the telescope when the…
• A beam of light of wavelength 720 nm in air enters water (refractive index = 4 3 ). Its wavelength in water will be:
• A ray of light travels from a denser to a rarer medium. After refraction, it bends away from the normal. When we keep…
• The focal length of the objective of a compound microscope is
• A thin glass (refractive index 1.5) lens has optical power of –8 D in air. Its optical power in a liquid medium with…
• A lens is a transparent medium bounded by two surfaces, with one or both surfaces being spherical. The focal length of…
• The apparent depth of a needle lying at the bottom of the tank, which is filled with water of refractive index 1.33 to…
• An object 2 cm high is placed at a distance of 16 cm from a concave mirror, which produces a real image 3 cm high. What…
• The optical density of turpentine is higher than that of water while its mass density is lower. Figure shows a layer of…
• The minimum distance between an object and its real image formed by a convex lens of focal length f is:
• The radius of curvature of the curved surface of a plano-convex lens is 20 cm. If the refractive index of the material…
• Two mirrors at an angle θ° produce 5 images of a point. The number of images produced when θ is decreased to θ° – 30° is
• A lens is a transparent medium bounded by two surfaces, with one or both surfaces being spherical. The focal length of…
• Which of the following is correct for light diverging from a point source?
• A real image of an object is formed at a distance of 20 cm from a lens. On putting another lens in contact with it, the…
• What is the refractive index of material of a plano-convex lens, if the radius of curvature of the convex surface is 10…
• A compound microscope consists of two converging lenses. One of them, of smaller aperture and smaller focal length is…
• The power of a biconvex lens is 10 dioptre and the radius of curvature of each surface is 10 cm. Then the refractive…
• For a glass prism, the angle of minimum deviation will be smallest for the light of
• Refraction of light from air to glass and from air to water are shown in figure (i) and figure (ii) below. The value of…
• A small telescope has an objective lens of focal length 144 cm and an eye piece of focal length 6.0 cm. What is the…
• A compound microscope has an objective and an eyepiece of focal lengths f_ o and f_ e , respectively. To obtain a large…
• A plano-convex lens ( f = 20 cm) is silvered at plane surface. The focal length will be
• From a point source a light falls on a spherical glass surface ( m = 1.5 and radius of curvature = 10 cm). The distance…
• A compound microscope consists of two converging lenses. One of them, of smaller aperture and smaller focal length is…
• A point object is placed at the centre of a glass sphere of radius 6 cm and refractive index 1.5. The distance of…
• A plano-convex lens is made of glass of refractive index 1.5.The focal length of the lens and radius of curvature R of…
• The refractive index of glass is 1.5 for light waves of l = 6000 Å in vacuum. Its wavelength in glass is
• A plane wavefront is incident on a concave mirror of radius of curvature R. The radius of the refracted wavefront will…
• A convergent beam of light passes through a diverging lens of focal length 0.2 m and comes to focus 0.3 m behind the…
• In a compound microscope, the focal lengths of two lenses are 1.5 cm and 6.25 cm. If an object is placed at 2 cm from…
• Two transparent media of refractive indices n 1 and n 2 are separated by a spherical transparent surface. The rays of…
• A vessel of depth x is half filled with oil of refractive index m 1 and the other half is filled with water of…
• Assertion (A): A ray of light is incident normally on the face of a prism. The emergent ray will graze along the…
• A biconvex lens of focal length f is cut into two identical plano convex lenses. The focal length of each part will be
• A concave mirror of focal length f 1 is placed at a distance of d from a convex lens of focal length f 2 . A beam of…
• The final image in an astronomical telescope with respect to object is
• Light travels in two media A and B with speeds 1.8 × 10 8 m s –1 and 2.4 × 10 8 m s –1 respectively. Then the critical…
• A converging lens is used to form an image on a screen. When the upper half of the lens is covered by an opaque screen,
• Assertion (A): In a reflecting telescope, the image does not have chromatic aberration. Reason (R): Chromatic…
• For a glass prism ( = 3 ) the angle of minimum deviation is equal to the angle of the prism. The angle of the prism is
• The plane face of a planoconvex lens is silvered. The refractive index of material and radius of curvature of the…
• A biconvex lens of glass having refractive index 1.47 is immersed in a liquid. It becomes invisible and behaves as a…
• Assertion (A): The image of an object placed between f and 2 f from a convex lens can be seen on a screen. If the…
• A plane wavefront is incident on a concave mirror of radius of curvature R. The radius of the reflected wavefront will…
• The refractive index of water is 1 33 . What will be the speed of light in water
• If _ 0 and _ 0 are the electric permittivity and magnetic permeability in free space, and are corresponding quantities…
• Which of the following forms a virtual and erect image for all positions of the object?
• Two transparent media of refractive indices n 1 and n 2 are separated by a spherical transparent surface. The rays of…
• A ray of light is incident on a thick slab of glass of thickness t as shown in the figure. The emergent ray is parallel…
• When an object is kept at a distance of 30 cm from a concave mirror, the image is formed at a distance of 10 cm. If the…
• Assertion (A): The angle of minimum deviation for a prism is lesser for red light than that for blue light. Reason (R)…
• A ray of light travels from a denser to a rarer medium. After refraction, it bends away from the normal. When we keep…
• When an object is placed between f and 2f of a concave mirror, the image formed is
• Assertion (A): Plane and convex mirrors cannot produce real images under any circumstance. Reason (R): A virtual image…
• A convex lens of radii of curvature 20 cm and 30 cm respectively. It is silvered at the surface which has smaller…
• A compound microscope consists of an objective lens with focal length 1.0 cm and eye piece of focal length 2.0 cm and a…
• The angle of minimum deviation for prism of angle p /3 is p /6, if the velocity of light in vacuum is 3 × 10 8 m s –1 …
• The diameter of the pupil of human eye is about 2 mm. Human eye is most sensitive to the wavelength of 555 nm. The…
• The frequency of a light wave in a material is 2 10 14 Hz and wavelength is 5000 A . The refractive index of material…
• A convex lens of focal length 0.2 m and made of glass ( ^a _g = 1.5 ) is immersed in water ( ^a _w = 1.33 ). Find the…
• A convex refracting surface of radius of curvature 20 cm separates two media of refractive indices 4/3 and 1.60. An…
• If the focal length of objective lens is increased then magnifying power of
• A microscope is focussed on a mark on a piece of paper and then a slab of glass of thickness 3 cm of refractive index…
• An air bubble in a glass sphere (μ = 1.5) is situated at a distance 3 cm from a convex surface of diameter 10 cm. At…
• An object is placed at a distance of 1.5 m from a screen and a convex lens is interposed between them. The…
• Two plane mirrors are placed parallel to each other at a distance L apart. A point object O placed between them, at a…
• A compound microscope consists of two converging lenses. One of them, of smaller aperture and smaller focal length is…
• A small telescope has an objective lens of focal length 140 cm and an eyepiece of focal length 5.0 cm. The magnifying…
• Assertion (A): Although the surfaces of a goggle lens are curved, it does not have any power. Reason (R): In case of…
• A ray of light of wavelength 600 nm propagates from air into a medium. If its wavelength in the medium becomes 400 nm…
• Two point white dots are 1 mm apart on a black paper. They are viewed by eye of pupil diameter 3 mm. Approximately…
• A glass slab ( = 1.5) of thickness 6 cm is placed over a paper. The shift in the letters printed on the paper will be:
• The focal length of a concave mirror in air is f . When the mirror is immersed in a liquid of refractive index 5 3 …
• Which of the following is not due to total internal reflection?
• A beam of light travels from air into a medium. Its speed and wavelength in the medium are 1.5 10 8 ms -1 and 230 nm…
• Assertion (A): A convex lens, when immersed in a liquid, disappears. Reason (R): The refractive indices of material of…
• A point object is placed in air at a distance of 4R on the principal axis of a convex spherical surface of radius of…
• A ray of light travels a distance of 12.0 m in a transparent sheet in 60 ns. The refractive index of the sheet is
• Light incident normally on a plane mirror attached to a galvanometer coil refracts backward as shown in figure. A…
• What can be the largest distance of an image of a real object from a convex mirror of radius of curvature is 20 cm?
• A boy of height 1 m stands in front of a convex mirror. His distance from the mirror is equal to its focal length. The…
• A reflecting telescope has a large mirror for its objective with radius of curvature equal to 80 cm. The magnifying…
• A plane wave is incident on a concave mirror of radius of curvature R. The reflected wave is a spherical wave of radius:
• A ray of light travels from a denser to a rarer medium. After refraction, it bends away from the normal. When we keep…
• A point source of light is placed at a depth of h below the surface of water of refractive index m . A floating opaque…
• For a total internal reflection, which of the following is correct?
• The magnification produced by a spherical mirror is -2 0 . The mirror used and the nature of the image formed will be
• The radii of curvature of the surfaces of a double convex lens are 20 cm and 40 cm respectively, and its focal length…
• A ray incident at a point at an angle of incidence of 60° enters a glass sphere of refractive index and is reflected…
• A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in such a way that its…
• A tank is filled with water to a height of 12.5 cm. The apparent depth of a needle lying at the bottom of the tank is…
• A ray of monochromatic light propagating in air, is incident on the surface of water. Which of the following will be…
• A ray of light passes through an equilateral prism (refractive index 1.5) such that angle of incidence is equal to…
• A square card of side length 1 mm is being seen through a magnifying lens of focal length 10 cm. The card is placed at…
• A small object lies at the bottom of a vessel filled with water (refractive index 4 3 ) up to a height H. When viewed…
• The relationship between angle of incidence i, prism of angle A and angle of minimum deviation for a triangular prism is
• A biconvex lens has a focal length 2/3 times the radius of curvature of either surface. The refractive index of the…
• There are certain material developed in laboratories which have a negative refractive index. A ray incident from air…
• In the diagram, a prism of angle 30° is used. A ray PQ is incident as shown. An emergent ray RS emerges perpendicular…
• Three immiscible liquids of densities d 1 > d 2 > d 3 and refractive indices μ 1 > μ 2 > μ 3 are put in a beaker. The…
• Two points separated by a distance of 0.1 mm can just be inspected in a microscope when light of wavelength 6000 Å is…
• Double convex lenses are to be manufactured from a glass of refractive index 1.55, with both faces of same radius of…
• A point source is placed at the bottom of a tank containing a transparent liquid (refractive index n ) to a depth H…
• A concave lens is placed in contact with a convex lens of focal length 25 cm. The combination produces a real image at…
• Two transparent media of refractive indices n 1 and n 2 are separated by a spherical transparent surface. The rays of…
• A lens is a transparent medium bounded by two surfaces, with one or both surfaces being spherical. The focal length of…
• A point luminous object ( O ) is at a distance h from front face of a glass slab of width d and of refractive index m …
• The focal length of a concave mirror is f. An object is placed at a distance x from the focus. The magnification is
• Two plane mirrors M 1 and M 2 are inclined at angle q as shown in the figure. A ray of light 1, which is parallel to M…
• A ray of light strikes a transparent rectangular slab of refractive index at an angle of incidence of 45°. The angle…
• In the given figure, the radius of curvature of curved surface for both the plano-convex and plano-concave lens is 10…
• Which of the following is correct for the beam which enters the medium?
• Two lenses of focal lengths 20 cm and −40 cm are held in contact. The image of an object at infinity will be formed by…
• An astronomical refractive telescope has an objective of focal length 20 m and an eyepiece of focal length 2 cm. Then
• A telescope is used to resolve two stars separated by 4.6 × 10 –6 rad. If the wavelength of light used is 5460 Å, what…
• The focal lengths of the objective and the eyepiece of a compound microscope are 1 cm and 2 cm respectively. If the…
• The far point of a near sighted person is 6.0 m from her eyes, and she wears contacts that enable her to see distant…
• A thin symmetrical double convex lens of power P is cut into three parts, as shown in the figure. Power of A is array c…
• A ray of light travels from a denser to a rarer medium. After refraction, it bends away from the normal. When we keep…
• A mark placed on the surface of a sphere is viewed through glass from a position directly opposite. If the diameter of…
• Two transparent media of refractive indices n 1 and n 2 are separated by a spherical transparent surface. The rays of…
• A man is trying to start a fire by focusing sunlight on a piece of paper using an equiconvex lens of focal length 10…
• Critical angle for light going from medium (i) to (ii) is θ. The speed of light in medium (i) is v , then the speed of…
• A compound microscope consists of two converging lenses. One of them, of smaller aperture and smaller focal length is…
• A ray of light travels from a denser to a rarer medium. After refraction, it bends away from the normal. When we keep…
• When light rays undergoes two internal reflection inside a raindrop, which of the rainbow is formed?
• Two beams of red and violet color are made to pass separately through a prism (angle of the prism is 60°). In the…
• Two transparent media of refractive indices n 1 and n 2 are separated by a spherical transparent surface. The rays of…
• An object approaches a convergent lens from the left of the lens with a uniform speed 5 m s –1 and stops at the focus…
• A giant refracting telescope at an observatory has an objective lens of focal length 15 m. If an eye piece of focal…
• A real image of a distance object is formed by a planoconvex lens on its principal axis. Spherical aberration is
• A person with normal near point 25 cm using a compound microscope with objective of focal length 8.0 mm and an eye…
• The radius of curvature of each surface of a convex lens of refractive index 1.5 is 40 cm. Its power is
• Light from a point source in air falls on a spherical glass surface of radius of curvature and refractive index are 20…
• The near point of a hypermetropic person is 75 cm from the eye. What is the power of the lens required to enable the…
• A compound microscope consists of two converging lenses. One of them, of smaller aperture and smaller focal length is…
• A plane mirror is placed along the x -axis facing negative y -axis. The mirror is fixed. A point object is moving with…
• A lens is a transparent medium bounded by two surfaces, with one or both surfaces being spherical. The focal length of…
• Critical angle of glass is θ 1 and that of water is θ 2 . The critical angle for water and glass surface would be (μ g…
• A ray of light travelling in a transparent medium of refractive index μ, falls on a surface separating the medium from…
• A lens having focal length f and aperture of diameter d forms an image of intensity I . Aperture of diameter in central…
• Two identical glass ( _ g = 3 2 ) equiconvex lenses of focal length f are kept in contact. The space between the two…
• A lens is a transparent medium bounded by two surfaces, with one or both surfaces being spherical. The focal length of…

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