Huygen's principle for secondary wavelets may be used to:

In a YDSE, let X and Y be the upper and lower slits. A thin film of thickness t and refractive index $\mu$ is placed in front of X. Let $\beta$ = fringe width. The central maximum will shift 

In the following question, a statement of assertion (A) is followed by a statement of the reason (R)

A: The maximum intensity in YDSE is four times the intensity due to each slit when they are identical.

R: The phase difference between the interfering waves is $2n\mathrm{\pi }$ at the position of maxima where n = 0, 1, 2, ......

In the following question, a statement of assertion (A) is followed by a statement of the reason (R)

A: No sustained interference pattern is obtained when two electric bulbs of the same power are taken.

R: Phase difference between waves coming out of electric bulbs is not constant.

In the following question, a statement of assertion (A) is followed by a statement of the reason (R)

A: When a thin transparent sheet is placed in front of one of the slits in YDSE, the fringe of zero-order shifts to some other position.

R: On placing this transparent sheet in front of a slit, the position of zero path difference on the screen changes.

In the following question, a statement of assertion (A) is followed by a statement of the reason (R).

A: Nicol prism is used to produce and analyze plane polarised light.

R: Nicol prism reduces the intensity of the light to zero.

In the following question, a statement of assertion (A) is followed by a statement of the reason (R)

A : If the background of two macroscopic objects is blue, then they are resolved well by microscope.

R : Resolving power is inversely proportional to the wavelength of light used.

In the following question, a statement of assertion (A) is followed by a statement of the reason (R)

A : On increasing the phase difference from$\frac{\mathrm{\pi }}{3} \mathrm{to} \frac{\mathrm{\pi }}{2}$ in YDSE, the intensity decreases by $\frac{1}{3}$rd.

R : $\mathrm{I}=4{\mathrm{I}}_0 {\cos }^2\frac{\mathrm{\theta }}{2}$ with usual symbol meanings.

The resolving power of an electron microscope is R, when accelerating potential is V. If accelerating potential is increased by 3 V, then its new resolving power is-

In young's experiment, the wavelength of red light is $7.8\times {10}^{-5}$ cm and that of blue light $5.2\times {10}^{-2}$ cm. The value of n for which (n+1)th blue bright band coincides with the nth red band is:

In Young's double-slit experiment, if the separation between coherent sources is halved and the distance of the screen from the coherent sources is doubled, then the fringe width becomes:

The Brewster's angle for an interface should be:

In Young’s double-slit experiment, the slits are separated by 0.28 mm and the screen is placed 1.4 m away. The distance between the central bright fringe and the fourth bright fringe is measured to be 1.2 cm. Determine the wavelength of light used in the experiment.

In Young’s double-slit experiment using monochromatic light of wavelength λ, the intensity of light at a point on the screen where path difference is λ is K units. What is the intensity of light at a point where path difference is λ/3?

$$\begin{gathered} \left(1\right) \frac{K}{3} \\ \left(2\right) \frac{K}{4} \\ \left(3\right) \frac{K}{2} \\ \left(4\right) K \end{gathered}$$

In a double-slit experiment the angular width of a fringe is found to be 0.2° on a screen placed 1 m away. The wavelength of light used is 600 nm. What will be the angular width of the fringe if the entire experimental apparatus is immersed in water? Take the refractive index of water to be 4/3.

What is the Brewster angle for air to glass transition? (Refractive index of glass = 1.5.)

What is the distance for which ray optics is a good approximation for an aperture of 4 mm and wavelength 400 nm?

When the light diverges from a point source, the shape of the wavefronts is:

When the light is coming from a distant star that is intercepted by the earth, the shape of the wavefront is:

Which of the following is not true?

A beam of light consisting of two wavelengths, 650 nm, and 520 nm, is used to obtain interference fringes in Young’s double-slit experiment. What is the distance of the third bright fringe on the screen from the central maximum for wavelength 650 nm?

$$\begin{gathered} \left(1\right) 1950\frac{D}{d} nm \\ \left(2\right) 1700 \frac{D}{d} nm \\ \left(3\right) 1100\frac{D}{d} nm \\ \left(4\right) 1861\frac{D}{d} nm \end{gathered}$$

In deriving the single slit diffraction pattern, at which angles the intensity is zero?

$$\begin{gathered} \left(1\right) \frac{2n\lambda }{a} \\ \left(2\right) \frac{n\lambda }{a} \\ \left(3\right) \frac{n\lambda }{2a} \\ \left(4\right) 0 \end{gathered}$$

A parallel beam of light of wavelength 500 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1 m away. It is observed that the first minimum is at a distance of 2.5 mm from the center of the screen. The width of the slit is:

Two towers on top of two hills are 40 km apart. The line joining them passes 50 m above a hill halfway between the towers. What is the longest wavelength of radio waves, which can be sent between the towers without appreciable diffraction effects?

In a double-slit experiment using the light of wavelength 600 nm, the angular width of a fringe formed on a distant screen is 0.1°. What is the spacing between the two slits?

$$\begin{gathered} \left(1\right) 3.44\times {10}^{-4} m \\ \left(2\right) 2.54\times {10}^{-4} m \\ \left(3\right) 1.31\times {10}^{-4} m \\ \left(4\right) 2.01\times {10}^{-4} m \end{gathered}$$

$$\begin{gathered} \left(1\right) 6.87\times {10}^5 m/s \\ \left(2\right) 4.75\times {10}^4 m/s \\ \left(3\right) 3.20\times {10}^5 m/s \\ \left(4\right) 5.45\times {10}^4 m/s \end{gathered}$$

The intensity at a point at a distance r from a source which produces cylindrical wavefronts varies as:

In YDSE, what should be the width of each slit to obtain 20 maxima of the double-slit pattern within the central maximum of the single slit pattern? (d = 1 mm)

Consider a light beam incident from air to a glass slab at Brewster's angle as shown in the figure. A polaroid is placed in the path of the emergent ray at point P and rotated about an axis passing through the centre and perpendicular to the plane of the polaroid,
                                    

Consider sunlight incident on a slit of width ${10}^4$ $\stackrel{\circ }{\mathrm{A}}$. The image seen through the slit shall