List of top Physics Questions on Wave optics asked in UP Board XII

Write down the formula for refraction of light from a spherical surface and with the help of this, derive the relation \( \frac{1}{f} = (n - 1) \left( \frac{1}{R_1} - \frac{1}{R_2} \right) \) for a thin lens. Also show that, the focal length for concave lens will be negative.
What is an astronomical telescope? Draw ray diagram for an astronomical telescope when final image is formed at infinity.
Which nature of light is supported by Young's double slit experiment? The light used in Young's double slit experiment contains two wavelengths, 6000 \AA\ and 5000 \AA. Separation between the slits is \(10^{-3}\) m and the screen is at a distance of 1 m from the slits. Find minimum distance from the central maxima where bright fringes for both the wavelengths are coincident.
Give pictorial representation of polarized and unpolarised light. Polarizing angle for a transparent medium is 60°. Find the value of angle of refraction and refractive index of the medium.
A concave lens of focal length -18 cm is placed in contact with a convex lens of focal length +12 cm. The focal length of the combination will be:
Explain the difference between interference and diffraction of light. Write the expression for the width of interference fringes in Young's double slit experiment and explain the effect of separation of slits and wavelength of light used on it.
In a single-slit diffraction pattern, the angle of diffraction for the second minimum is $60^\circ$. Find the width of the slit in terms of $\lambda$.
Explain the meaning of polarisation of light and show the difference between polarised and unpolarised light with the help of a suitable diagram.
Write the formula of refraction of light through a single spherical surface. The radius of curvature of one end of a cylindrical glass (n = 1.5) rod is 2 cm. Find the position and nature of the image of the point source S. See the figure and also draw the ray diagram.
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Write down the formula for the distances of nth bright and nth dark fringes, from the central fringe in Young's double slit experiment. A monochromatic source of light with wavelength 480 nm, is used in this experiment, in which distance between the double slits is 3 mm. Distance between the slits and screen is 2 m. Find the distance between the 8th bright and the 3rd dark fringes.
Obtain the formula for the width of central maxima from the experiment of diffraction of light through a single slit and draw the diagram of the intensity distribution of the light obtained on the screen.
Mention any two applications of total internal reflection.
If polarising angle is \( \theta_1 \), and critical angle is \( \theta_2 \), then:
Mention the required conditions for the interference of light. In Young's double slit experiment, the intensity of light at a point on the screen is \( I \), when path difference is \( \lambda \) by using monochromatic light of wavelength \( \lambda \). Find the intensity of light at that point, where path difference is \( \frac{\lambda}{4} \).
In between two crossed polaroids A and B, a third polaroid C is placed in such a way that its polarising axis makes an angle \( \theta \) from the polarising axis of the polaroid A. If the intensity of the transmitted light from the polaroid A is \( I_0 \), then find out the intensity of the polarised light transmitted from the polaroid B. For which angle \( \theta \) the intensity of the transmitted light will be maximum?
What is Brewster's law?
What is plane-polarised light ? How the ordinary light, partially polarised light and totally polarised light are distinguished with the help of a polaroid ?
Using monochromatic light of wavelength \(\lambda\), in Young's double slit experiment, at a point on the screen where path difference is \(\lambda\) between the two waves, the intensity of light is K units. Find the intensity of light at a point on the screen where path difference is \(\frac{\lambda}{3}\).
Elucidate the diffraction of monochromatic light by narrow slit. Determine the expression for angular width of central maximum.
What is meant by polarization of light? Describe a method to obtain plane polarized light by reflection.
How will you detect plane polarized light by polaroid?
What do you understand by coherent source?
Establish the formula for focal length of combination of two thin lenses placed in contact.
What is meant by interference and diffraction of light ? Write the conditions of interference.
Draw a ray diagram of reflecting telescope. Explain its working.