Optics Questions

The angular resolution of a 10 cm diameter telescope at a wavelength of 5000 Å is of the order of :

The angular resolution of a 10 cm diameter telescope at a wavelength of 5000 Å is of the order of :

A small coin is resting on the bottom of a beaker filled with a liquid. A ray of light from the coin travels up to the surface of the liquid and moves along its surface. How fast is the light traveling in the liquid?

The frequency of a light wave in a material is $2\times 10^{14}\text{Hz}$ and wavelength is $5000\text{A˚}$. The refractive index of material will be:

A lens having focal length $f$ and aperture of diameter $d$ forms an image of intensity $I$. Aperture of diameter $d/2$ in central region of lens is covered by a black paper. Focal length of lens and intensity of image now will be respectively:

A ray of light travelling in a transparent medium of refractive index $\mu$, falls on a surface separating the medium from air at an angle of incidence of $45^{\circ }$. For which of the following values of $\mu$ the ray can undergo total internal reflection?

A converging beam of rays incident on a diverging lens intersects at $15\text{cm}$ on the opposite side. If the lens is removed, they meet $5\text{cm}$ closer. The focal length is:

A $15^{\circ }$ prism (${\mu }_1=1.5$) is combined with another (${\mu }_2=1.75$) to produce dispersion without deviation. The angle of the second prism is:

A plano-convex lens (${\mu }_1$) fits exactly into a plano-concave lens (${\mu }_2$). Their plane surfaces are parallel. Focal length of the combination is:

For a normal eye, the cornea provides power of $40\text{D}$ and the eye lens provides $20\text{D}$. The estimated distance between the retina and the lens is:

In YDSE, slits are $2\text{mm}$ apart and $D=2\text{m}$. Two wavelengths ${\lambda }_1=12000\text{A˚}$ and ${\lambda }_2=10000\text{A˚}$ are used. At what minimum distance from the central fringe will their bright fringes coincide?

A parallel beam of fast moving electrons is incident normally on a narrow slit. If the speed of electrons is increased:

At the first minimum adjacent to the central maximum of a single-slit diffraction pattern, the phase difference between the Huygen's wavelet from the edge of the slit and the wavelet from the midpoint of the slit is:

Two slits in Young’s experiment have widths in the ratio $1:25$. The ratio of intensity at the maxima and minima in the interference pattern, $\frac{I_{max}}{I_{min}}$ is:

In an astronomical telescope in normal adjustment, a straight black line of the length $L$ is drawn on the objective lens. The eye-piece forms a real image of this line. The length of this image is $I$. The magnification of the telescope is:

A beam of light consisting of red, green and blue colours is incident on a right angled prism. The refractive index of the material of the prism for the above red, green and blue wavelengths are $1.39,1.44$ and $1.47$ respectively. The prism will: