When a parallel beam of white light incident on convex lens split into different colours the phenomenon is called.
When a parallel beam of white light incident on convex lens split into different colours the phenomenon is called.
Spherical aberration
Chromatic aberration
Polarization
Diffraction
The Correct Option is B
Solution and Explanation
The correct option is B
Top Questions on Ray optics and optical instruments
Inductance of a coil with \(10^4\) turns is \(10\,\text{mH}\) and it is connected to a DC source of \(10\,\text{V}\) with internal resistance \(10\,\Omega\). The energy density in the inductor when the current reaches \( \left(\frac{1}{e}\right) \) of its maximum value is \[ \alpha \pi \times \frac{1}{e^2}\ \text{J m}^{-3}. \] The value of \( \alpha \) is _________.
\[ (\mu_0 = 4\pi \times 10^{-7}\ \text{TmA}^{-1}) \]- JEE Main - 2026
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- A collimated beam of light of diameter 2 mm is propagating along the x-axis. The beam is required to be expanded into a collimated beam of diameter 14 mm using a system of two convex lenses. If the first lens has focal length 40 mm, then the focal length of the second lens is_____ mm.
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- In a microscope, the objective has a focal length \(f_o=2\) cm and the eye-piece has a focal length \(f_e=4\) cm. The tube length is 32 cm. The magnification produced by this microscope for normal adjustment is_____.
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- In parallax method for the determination of focal length of a concave mirror, the object should always be placed:
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\(XPQY\) is a vertical smooth long loop having a total resistance \(R\), where \(PX\) is parallel to \(QY\) and the separation between them is \(l\). A constant magnetic field \(B\) perpendicular to the plane of the loop exists in the entire space. A rod \(CD\) of length \(L\,(L>l)\) and mass \(m\) is made to slide down from rest under gravity as shown. The terminal speed acquired by the rod is _______ m/s.
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Questions Asked in JEE Main exam
- Identify the correct statements: The presence of –NO\(_2\) group in benzene ring A. activates the ring towards electrophilic substitutions. B. deactivates the ring towards electrophilic substitutions. C. activates the ring towards nucleophilic substitutions. D. deactivates the ring towards nucleophilic substitutions. Choose the correct answer from the options given below:
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- General Chemistry
- Let $\vec{a}=2\hat{i}-\hat{j}-\hat{k}$, $\vec{b}=\hat{i}+3\hat{j}-\hat{k}$ and $\vec{c}=2\hat{i}+\hat{j}+3\hat{k}$. Let $\vec{v}$ be the vector in the plane of $\vec{a}$ and $\vec{b}$, such that the length of its projection on the vector $\vec{c}$ is $\dfrac{1}{\sqrt{14}}$. Then $|\vec{v}|$ is equal to
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A substance 'X' (1.5 g) dissolved in 150 g of a solvent 'Y' (molar mass = 300 g mol$^{-1}$) led to an elevation of the boiling point by 0.5 K. The relative lowering in the vapour pressure of the solvent 'Y' is $____________ \(\times 10^{-2}\). (nearest integer)
[Given : $K_{b}$ of the solvent = 5.0 K kg mol$^{-1}$]
Assume the solution to be dilute and no association or dissociation of X takes place in solution.- JEE Main - 2026
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- The wavelength of photon 'A' is 400 nm. The frequency of photon 'B' is \(10^{16}\,\text{s}^{-1}\). The wave number of photon 'C' is \(10^{5}\,\text{cm}^{-1}\). The correct order of energy of these photons is:
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- Given below are two statements: Statement I: The increasing order of boiling point of hydrogen halides is HCl<HBr<HI<HF. Statement II: The increasing order of melting point of hydrogen halides is HCl<HBr<HF<HI. In the light of the above statements, choose the correct answer from the options given below:
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Concepts Used:
Refraction of Light
Refraction is the bending of a wave when it enters a medium where its speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal boundary between the two media. The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's Law.
If you ever observe a pencil dipped into water, you’ll notice that it seems to be tilted at an angle at the interface of air and water, or the bottom of a tub or a tank that contains water seems to be raised. This phenomenon is caused due to the process of refraction of light. Refraction of light is the bending of the light wave, passing from one medium to another, which is caused due to the difference in the density of the two mediums.
Reason behind Refraction
The main cause of refraction is the variation in the velocity of the light when it enters different mediums. The speed of light in the air is faster than that of water. So, the speed of the light increases when it travels from water to air, and similarly, the speed decreases when it travels from air to water.
In the below figure, it is shown why the printed alphabets appear to have risen when seen through a glass slab. This is because when the light travels from air to glass, the speed gets reduced and the light moves toward the normal, that is the light rays move towards the NN’ normal from its original path. Likewise, when the light ray travels from glass to air, its speed gets increased and it moves away from the normal.
Refraction of Light in Reality
- Twinkling of the stars - The atmosphere is composed of areas of the thick and thin atmosphere. When one looks at the stars at night, the light passing through these different layers of the atmosphere from the stars reaches our eyes and therefore the stars appear to twinkle.
- As the light travels from the bottom to the top, the light coming from the pool bends due to refraction and thus the swimming pool always looks shallower than it really is.
- Due to the refraction of light, white light when passed through a prism splits into red, orange, yellow, green, blue and violet colours.
Laws of Refraction of Light
There are two Laws of Refraction. They are:
- The incident ray, the normal to the interface of two media, and the refracted ray, all lie on the same plane.
- Snell's Law: Snell’s law states that the ratio of the sine of the incident angle to the sin of refracted is constant. It describes the relationship between angles of refraction and angles of incidence.