Wave Optics - Optics - Physics Previous Year Questions

The angular width of a fringe in a double slit experiment is found to be $0.2^{\circ}$ on a screen 1 m away the wavelength of light used is 600 nm . The change in angular width of the fringe, if the entire measurement system is immersed in water is [use refractive index of water as $4 / 3$ ]

A Young's double slit experiment apparatus has slits separated by 0.2 mm and a screen 60 cm away from the slits. The whole apparatus is immersed in a liquid medium of refractive index $11 / 9$ and the slits are illuminated with green light ( $\lambda=550$ nm in vacuum). Find the fringe width of the pattern formed on the screen.

If the slit width is 2 mm and wavelength of light used is $4000\mathop {\rm{A}}\limits^{\rm{o}}$, then Fresnel distance is nearly

Two slits separated by a distance of 1 mm are illuminated with light of wavelength $6.5 \times 10^{-7} \mathrm{~m}$. The interference fringes are observed on a screen placed at 1 m from the slits. The distance between the third dark fringe and the fifth bright fringe is equal to

Two slits are made one millimetre apart and the screen is placed one metre away from the slits. The fringe width when light of wavelength 500 nm is used is

A point source of light is placed at the focus of a concave mirror. Consider only paraxial rays. The shapes of the wavefronts of incident and reflected lights respectively are

The limit of resolution of a telescope is $3.0 \times 10^{-7} \mathrm{rad}$. Assuming that it is used to see the light of wavelength 525 nm from a star, what should be the diameter of the objective?

Young's double slit experiment is carried out by using green, red and blue light, one colour at a time. The fringe width recorded are $\beta_{G^{\prime}} \beta_{R^{\prime}} \beta_B$ respectively, then

On using red light $(\lambda=6600 \mathop {\rm{A}}\limits^{\rm{o}})$ in Young's double slit experiment, 60 fringes are observed in the field of view. If violet light ( $\lambda=4400 \mathop {\rm{A}}\limits^{\rm{o}}$ ) is used, the number of fringes observed will be

In a double slit experiment performed in air, the angular width of a fringe is found to be $0.15^{\circ}$ on a screen placed 80 cm away. The wavelength of light is used 490 nm . The angular width of the fringe, if the entire apparatus is immersed in a medium of refractive index $\frac{5}{3}$ is

In Young's double slit experiment for what order does the wavelength of red light $(\lambda=780 \mathrm{~nm})$ coincide with $(n+1)$ th order of blue light $(\lambda=520 \mathrm{~nm})$ ?

In a Young's double slit experiment, if the distance between two slits is reduced by a factor of 2 and the wavelength of light is increased 4 times then the distance between two maxima will become $\_\_\_\_$ times the original value

In an interference pattern of Young's double slit experiment, at a point we observe the 12 th order maximum for a monochromatic light source with wavelength $6000 \mathop {\rm{A}}\limits^{\rm{o}} $. What order will be visible here, if the source is replaced by a light of wavelength $4800 \mathop {\rm{A}}\limits^{\rm{o}} $ ?

Wavelength of light used in an optical instruments are $\lambda_1=4000 \mathop {\rm{A}}\limits^{\rm{o}}$ and $\lambda_2=5000 \mathop {\rm{A}}\limits^{\rm{o}}$, then the ratio of their respective resolving powers (corresponding to $\lambda_1$ and $\lambda_2$ ) is

What minimum separation between two objects a human eye would be able to resolve, if the eye pupil diameter is 2 mm and the two objects are 20 m away from the eye?

(Assume, human eye to be equivalent to a convex lens and consider the average wave length of light as 600 nm )

The shape of wavefront of light diverging from point source

Which of the following phenomena produces the colour in soap bubble?

If in a Young's double slit experiment the slit separation is doubled and the distance of the screen from the slits is reduced to half, then the fringe widths become how many times their original value?