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Lenses for GUJCET: 27 solved questions

Real GUJCET paper questions on lenses, part of ray optics and optical instruments. Each opens with the options, the correct answer and a step-by-step solution. Papers run from 2009 to 2026. No sign-in needed to read them.

What this topic asks

• Lens maker's formula and power — 17 questions
• Combinations and silvered lenses — 9 questions
• Lens formula and magnification — 1 question

All 27 questions with solutions

• A convex lens is immersed in a liquid whose refractive index is equal to the refractive index of the material… GUJCET 2009
• A transparent plastic bag filled with air forms a concave lens. Now, if this bag is completely immersed in wa… GUJCET 2011
• The figure shows three arrangements, P, Q and R, of two lenses each. The radii of curvature of all the curved… GUJCET 2011
• A plano-convex lens fits exactly into a plano-concave lens as shown in the figure. Their plane surfaces are p… GUJCET 2014
• The optical interval between two thin lenses having focal lengths f₁ and f₂ and separated by a distance d is . GUJCET 2016
• Two thin lenses of focal lengths f₁ and f₂ are in contact and coaxial. The power of the combination is . GUJCET 2018
• A plano-convex lens is made of material having refractive index 1.5. The radius of curvature of the curved su… GUJCET 2018
• The focal length of a thin lens made from a material of refractive index 1.5 is 15 cm. When it is placed in a… GUJCET 2019
• For a glass lens f=+50 cm. Then the power of the lens is . GUJCET 2020
• A lens (n = 1.5) is placed in a liquid. To make it disappear, the value of n of the liquid should be . GUJCET 2020
• The radii of curvature of the faces of a double convex lens are 10 cm and 15 cm. Its focal length is 12 cm. W… GUJCET 2021
• Find the equivalent focal length of a combination of two convex lenses in contact, the focal length of each o… GUJCET 2021
• Double-convex lenses are to be manufactured from a glass of refractive index 1.55, with both faces of the sam… GUJCET 2022
• What is the focal length of the combination of a convex lens of focal length 30 cm in contact with a concave… GUJCET 2022
• A lens has a power of -4.0 dioptre. It means . GUJCET 2023
• What is the power of combination of convex lens and concave lens of equal focal length 25 cm? GUJCET 2025
• Two thin convex lenses of focal length f₁ and f₂ are placed in contact with each other. The equivalent power… GUJCET 2026
• The radii of curvature of both the sides of a convex lens are 15 cm and the refractive index of the material… GSEB Board July 2015
• The focal length of a thin lens made from the material of refractive index 1.5 is 20 cm. When it is placed in… GSEB Board July 2016
• The focal length of an equiconvex lens in air is equal to either of its radii of curvature. The refractive in… GSEB Board July 2016
• For a thin convex lens, when the height of the object is double that of its image, its object distance is equ… GSEB Board July 2017
• A magician during a show makes a glass lens with n=1.47 disappear in a trough of liquid. What is the refracti… GSEB Board March 2020
• A magician during a show makes a glass lens with n = 1.47 disappear in a trough of liquid. The refractive ind… GSEB Board August 2020
• If the focal length of a converging lens is 0.25 m then the power of this lens is dioptre. GSEB Board July 2021
• A magician during a show makes a glass lens with refractive index n=1.5 disappear in a trough of liquid. The… GSEB Board March 2022
• What is the focal length of the combination of a convex lens of focal length 20 cm in contact with a concave… GSEB Board July 2023
• For a thin convex glass lens with radius of curvature 20 cm, the focal length is cm. The refractive index n o… RS Academy GUJCET booklet