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Ray Optics and Optical Instruments - ISC Class 12 Physics Questions with Answers

101 past-paper questions on Ray Optics and Optical Instruments from ISC Class 12 Physics papers (2027-2018), newest first. Open one to see its answer.

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A student uses two prisms, A and B, made of different materials but having the same prism angle ($60^\circ$). Prism Minimum… 2027 · 3 marks · Numerical
How can the focal length of a given convex lens be measured in Physics laboratory using only a metre scale? 2027 · 1 mark · Short answer
The focal length of a convex mirror will increase, if the mirror is placed in water. 2027 · 1 mark · Assertion-reason
In an astronomical telescope of refracting type, 2027 · 1 mark · MCQ
Answer the following questions: An equiconvex lens forms a full size magnified image of a candle flame on a screen. How will this… 2027 · 3 marks · Short answer
An innovative optical sensor system for a miniature drone incorporates a combination of various optical elements. A beam of light… 2027 · 5 marks · Case based
When a beam of white light is incident on a prism, the prism: (Understanding) 2026 · 1 mark · MCQ
Consider two thin lenses, M and N having focal lengths of $f_{1}$ and $f_{2}$, respectively. They are kept in contact with each… 2026 · 3 marks · Derivation
Answer the following questions: A student studies details of a microorganism with the help of an instrument. Name the instrument… 2026 · 3 marks · Drawing
Calculate the position of an object to be placed in front of a convex lens having focal length of 5cm to obtain an image which is… 2026 · 2 marks · Numerical
Why are giant telescopes of reflecting type? Give any one scientific reason. (Recall) 2026 · 1 mark · Short answer
A thin convex lens of power 5D is kept in contact with a thin concave lens of power 8D. Calculate the focal length of the… 2026 · 1 mark · Numerical
The focal length of the convex mirror will increase, if the mirror is placed in water. Given below are two statements marked… 2026 · 1 mark · Assertion-reason
State any one difference between a primary rainbow and a secondary rainbow. 2026 · 1 mark · Short answer
A microscope is focused on a mark at the bottom of a beaker. Water having refractive index of $\frac{4}{3}$ is poured into the… 2026 · 1 mark · MCQ
When a biconvex lens of glass of refractive index 1.6 was dipped in a certain transparent liquid, it was found to behave like a… 2026 · 1 mark · MCQ
Two similar convex lenses are made up of two different materials as shown in Figures 7 and 8 below. Find the number of images… 2026 · 2 marks · Short answer
Answer the following questions: A compound microscope has a magnifying power of 30. The focal length of its eye piece is 5cm. If… 2026 · 3 marks · Short answer
Give any one example where a ray of light travelling from one optical medium to another travels undeviated. (Understanding) 2026 · 1 mark · Short answer
A bi-convex lens of focal length $f_{1}$ is placed in air as shown in Figure 3(a) below. The radii of curvature of its first and… 2026 · 2 marks · Numerical
A monochromatic ray of light incident on one refracting surface of an equilateral prism, suffers a deviation as shown in the… 2026 · 3 marks · Short answer
Draw a labelled diagram of an astronomical telescope when its final image lies at infinity. 2026 · 3 marks · Drawing
The image below shows a compound microscope. Which one of the two lenses $L_{1}$ or $L_{2}$ has a larger focal length? 2026 · 1 mark · One word
With reference to the lens maker’s formula, answer the following questions: (Understanding) Apply the formula (expression) of… 2026 · 3 marks · Derivation
A virologist studies details of a virus with the help of an instrument. Name the instrument used by him. Draw a labelled ray… 2025 · 3 marks · Short answer
The focal length of a double convex lens is equal to the radius of curvature of either surface. What is the refractive index of… 2025 · 2 marks · Short answer
Two convex lenses having focal length of $1.5\text{ cm}$ and $5\text{ cm}$ are placed coaxially to form a compound microscope… 2025 · 3 marks · Numerical
A lens of focal length $f$ is divided into two equal parts and then these parts are put in a combination as shown in Figure 8… 2025 · 3 marks · Short answer
Figure 3 below shows an optical pin kept in front of a lens mirror combination. It is found that the final image formed by the… 2025 · 1 mark · Drawing
How is the refractive index of the material of a prism dependent on the angle of incidence? 2025 · 1 mark · Short answer
For any prism, show that refractive index ‘$n$’ of its material is given by… 2025 · 3 marks · Derivation
Three lenses $L_1$, $L_2$, and $L_3$ are specified in the given table below. To construct an astronomical telescope, which one of… 2025 · 1 mark · MCQ
When a convex lens made of glass is completely immersed in water, its focal length increases. 2025 · 1 mark · Assertion-reason
Based on the student's attempt to draw a ray diagram of a compound microscope: Identify two errors in the student's attempt to… 2025 · 3 marks · Long answer
For the given $|m|$ versus $|v|$ graph of a spherical mirror: Name the type of mirror used here. What is its focal length? 2025 · 2 marks · Short answer
When a beam of white light is passed through a prism, it gets split into its constituent colours. 2025 · 1 mark · Assertion-reason
If critical angle of glass-air pair ($\mu_g = 3/2$) is $\theta_1$ and that of water-air pair ($\mu_w = 4/3$) is $\theta_2$, then… 2025 · 1 mark · Assertion-reason
Both students i.e. Student 1 and Student 2, had an intention of stargazing at night and knew that a telescope would be required… 2025 · 3 marks · Long answer
A lens forms the image of an object as shown in the figure. Identify the type of lens. 2025 · 1 mark · Short answer
Calculate the refractive index of the material of the prism. 2025 · 2 marks · Numerical
If you had to construct an optical fibre using the two materials, which would you prefer for the core and the cladding? X: with a… 2025 · 1 mark · Short answer
Why does a car driver use a convex mirror as a rear-view mirror? 2025 · 1 mark · Short answer
A thin convex lens of focal length f is cut into parts and then combined as shown in Fig 1 and Fig 2. Evaluate the focal length… 2025 · 2 marks · Short answer
The graph for 'v' versus 'u' of a concave mirror forming real images, falls within the second quadrant. 2025 · 1 mark · Assertion-reason
Hubble telescope employs a large parabolic mirror as an objective. State any one advantage of using a mirror in place of a lens… 2025 · 1 mark · Short answer
The objective of a telescope consists of two lenses kept in contact. One lens has an optical power of $+2.0\text{ D}$ whereas the… 2025 · 2 marks · Numerical
Identify the optical device shown in Figure 2 below. 2025 · 1 mark · Short answer
Two identical thin convex lenses, each having an optical power of $2\text{ D}$ are kept in contact with each other. Calculate… 2025 · 3 marks · Numerical
For a science project, two fish tanks with lids were constructed as shown in the figure. Tank X has a lid with a convex shape… 2025 · 3 marks · Numerical
An astronomical telescope has an objective lens having large focal length. 2025 · 1 mark · Assertion-reason
A convex lens having small focal length is to be used as a magnifying glass (simple microscope) to obtain an image of a small… 2025 · 3 marks · Short answer
State any one difference between a primary rainbow and a secondary rainbow. 2025 · 1 mark · Short answer
Which material is used to make this glass slab? 2025 · 2 marks · Short answer
The teacher is demonstrating the experiment of the focal length of a convex lens using the u-v method. After the teacher takes… 2025 · 3 marks · Long answer
A student is performing an experiment to determine focal length of a convex lens by using an optical bench. State whether the… 2024 · 3 marks · Short answer
Figure 5 below shows a ray of monochromatic light LM incident on the first surface AB of a regular (equilateral) glass prism ABC… 2024 · 3 marks · Numerical
When a ray of white light is incident obliquely on the first surface of a prism, then 2024 · 1 mark · MCQ
There are two types of optical instruments: Microscopes and Telescopes. Microscopes are used to magnify very tiny objects whereas… 2024 · 5 marks · Case based
If an object is placed at a distance of $10\text{ cm}$ in front of a concave mirror of focal length $20\text{ cm}$, the image… 2023 · 1 mark · MCQ
Obtain an expression for refraction at a single convex spherical surface i.e., the relation between $\mu_1$ (rarer medium)… 2023 · 3 marks · Derivation
Derive Lens Maker’s formula. 2023 · 3 marks · Derivation
Draw a neat and labelled ray diagram to show the formation of a primary rainbow. 2023 · 2 marks · Drawing
Optical instruments are of great utility. They help us in studying very tiny objects as well as very large heavenly bodies… 2023 · 5 marks · Case based
What is meant by a microscope in normal use? 2023 · 1 mark · Short answer
Two thin lenses having optical powers of $-8\text{ D}$ and $+12\text{ D}$ are placed in contact with each other. The focal length… 2023 · 1 mark · MCQ
There are two types of lenses: Converging lenses and Diverging lenses, depending on whether they converge or diverge an incident… 2023 · 5 marks · Case based
Obtain Prism formula i.e. prove that $n = \frac{\sin\left(\frac{A + \delta_m}{2}\right)}{\sin\left(\frac{A}{2}\right)}$ Where the… 2023 · 3 marks · Derivation
Name any two phenomena which take place in the formation of a rainbow. 2023 · 2 marks · Short answer
For any prism, obtain a relation between angle of the prism ($A$), angle of minimum deviation ($\delta_m$) and refractive index… 2023 · 3 marks · Derivation
Define angular dispersion. State any one difference between a primary rainbow and a secondary rainbow. 2022 · 2 marks · Short answer
A thin converging lens of focal length $12\text{ cm}$ is kept in contact with a thin diverging lens of focal length… 2022 · 2 marks · Numerical
In case of a regular prism, in minimum deviation position, angle made by the refracted ray (inside the prism) with the normal… 2022 · 1 mark · MCQ
A thin converging lens of focal length $5\text{ cm}$ is used as a simple microscope. Calculate its magnifying power when image… 2022 · 2 marks · Numerical
Draw a ray diagram of a refracting astronomical telescope when final image is formed at infinity. Also write the expression for… 2022 · 3 marks · Drawing
Radius of curvature of an equi – convex lens of glass ($n = 1\cdot5$) is $30\text{ cm}$. Find its focal length. An object of… 2022 · 3 marks · Numerical
Where will you keep an object in front of a: Convex lens in order to get a virtual and magnified image? Concave mirror to get a… 2020 · 2 marks · Short answer
Draw a labelled graph of angle of deviation ($\delta$) versus angle of incidence ($i$) for a prism. 2020 · 2 marks · Drawing
For two thin lenses kept in contact with each other, show that: $\frac{1}{F} = \frac{1}{f_1} + \frac{1}{f_2}$ where the terms… 2020 · 3 marks · Derivation
In an astronomical telescope of refracting type: 2020 · 1 mark · MCQ
A compound microscope consists of two convex lenses having focal length of $1\cdot5\text{ cm}$ and $5\text{ cm}$. When an object… 2020 · 3 marks · Numerical
Name the physical principle on the basis of which optical fibres work. 2020 · 1 mark · Short answer
Derive an expression for refraction at a single (convex) spherical surface, i.e. a relation between $u$, $v$, $R$, $n_1$ (rarer… 2020 · 5 marks · Short answer
Calculate the focal length of a convex lens whose radii of curvature of two surfaces is $10\text{ cm}$ and $15\text{ cm}$… 2019 · 3 marks · Numerical
Define critical angle for a given medium. 2019 · 1 mark · Short answer
A ray of light is incident on a prism whose refractive index is $1\cdot52$ at an angle of $40^\circ$. If the angle of emergence… 2019 · 3 marks · Numerical
Write any one use for each of the following mirrors: Convex Concave 2019 · 2 marks · Short answer
The deviation produced for violet, yellow and red lights for crown glass are $3\cdot75^\circ$, $3\cdot25^\circ$ and… 2019 · 2 marks · Numerical
Draw a neat labelled ray diagram showing the formation of an image at the least distance of distinct vision D by a simple… 2019 · 5 marks · Derivation
Obtain an expression for refraction at a single convex spherical surface separating the two media having refractive indices… 2018 · 3 marks · Derivation
A thin convex lens of focal length $20\text{ cm}$ is kept in contact with a thin concave lens of focal length $15\text{ cm}$… 2018 · 2 marks · Numerical
An object is kept on the principal axis of a concave mirror of focal length $10\text{ cm}$, at a distance of $15\text{ cm}$ from… 2018 · 1 mark · MCQ
Derive $R = 2f$ for a spherical mirror, where the symbols have their usual meaning. 2018 · 3 marks · Derivation
Draw a labelled ray diagram of an image formed by a compound microscope with final image formed at the least distance of distinct… 2018 · 5 marks · Derivation
Complete the ray diagram shown in Figure 1, given that the critical angle for air-glass pair is $i_c = 42^\circ$. 2018 · 1 mark · Drawing
State any two differences between primary rainbow and secondary rainbow. 2018 · 2 marks · Short answer
Draw a labelled ray diagram of an image formed by a refracting telescope with final image formed at infinity. Derive an… 2018 · 5 marks · Drawing
When two thin lenses are kept in contact, prove that their combined or effective focal length F is given by… 2018 · 3 marks · Derivation
A convex lens, made of glass, is immersed in water. As a result, its focal length will: 2018 · 1 mark · MCQ
A biconvex lens made of glass (refractive index $1\cdot5$) has two spherical surfaces having radii $20\text{ cm}$ and… 2018 · 2 marks · Numerical
What is meant by dispersive power? Write an expression of dispersive power in terms of refractive indices. 2018 · 2 marks · Short answer
For any prism, prove that: $'n'\text{ or }\mu = \frac{\sin\left(\frac{A + \delta_m}{2}\right)}{\sin\left(\frac{A}{2}\right)}$… 2018 · 3 marks · Derivation

Ray Optics and Optical Instruments - ISC Class 12 Physics Questions with Answers

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