Ray Optics Test...

F₁ and F₂ are focal lengths of objective and eye piece respectively of the telescope. The angular magnification for the given telescope is equal to

A Galilean telescope has an objective of focal length 100 cm and magnifying power 50. The distance between the two lenses in normal

Wavelength of light used in an optical instrument are λ₁ = 4000 Å and λ₂ = 5000 Å , then ratio of their respective resolving powers (corresponding to λ₁ and λ₂) is

The aperture of the objective lens of a telescope is made large so as to

A transparent thin film of uniform thickness and refractive index n₁ =1.4 is coated on the convex spherical surface of radius R at one end of a long solid glass cylinder of refractive index n₂ = 1.5, as shown in the figure. Rays of light parallel to the axis of the cylinder traversing through the film from air to glass get focused at distance f₁ from the film, while rays of light traversing from glass to air get focused at distance f₂ from the film. Then,

A point source S is placed at the bottom of a transparent block of height 10 mm and refractive index 2.72. It is immersed in a lower refractive index liquid as shown in the figure. It is found that the light emerging from the block to the liquid forms a circular bright spot of diameter 11.54 mm on the top of the block. The refractive index of the

A microscope is focused at a point at the bottom of a beaker containing water. The microscope is then raised through 3 cm. To what height water must be added into the beaker to bring the point again in focus?

Wavelength of given light waves in air and in a medium are 6000 Å and 4000 Å respectively. The critical angle is

A prism having refractive index 1.414 and refracting angle 30° has one of the refracting surfaces silvered. A beam of light incident on the other refracting surface will retrace its path, if the angle of incidence is