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
20
Aug
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 In total internal reflection when the angle of incidence is equal [...]
A plano-convex lens fits exactly into a plano-concave lens. Their plane surfaces are parallel to each other. If the lenses are made of different material of refractive indices μ1 and μ2 and R is the radius of curvature of the curved surface of the lenses, then focal length of the combination is
20
Aug
A plano-convex lens fits exactly into a plano-concave lens. Their plane surfaces are parallel to each other. If the lenses are made of different material of refractive indices μ1 and μ2 and R is the radius of curvature of the curved surface of the lenses, then focal length of the combination is In total internal [...]
Two identical thin plano-convex glass lenses (refractive index 1.5) each having radius of curvature of 20 cm are placed with their convex surfaces in contact at the centre. The intervening space is filled with oil of refractive index 1.7. The focal length of the combination is
20
Aug
Two identical thin plano-convex glass lenses (refractive index 1.5) each having radius of curvature of 20 cm are placed with their convex surfaces in contact at the centre. The intervening space is filled with oil of refractive index 1.7. The focal length of the combination is In total internal reflection when the angle of incidence [...]
Two similar thin equi-convex lenses, of focal length f each, are kept co-axially in contact with each other such that the focal length of the combination is F1. When the space between the two lenses is filled with glycerin (which has the same refractive index (μ=1.5) as that of glass) then the equivalent focal length is F2. The ratio F1:F2 will be
20
Aug
Two similar thin equi-convex lenses, of focal length f each, are kept co-axially in contact with each other such that the focal length of the combination is F1. When the space between the two lenses is filled with glycerin (which has the same refractive index (μ=1.5) as that of glass) then the equivalent focal length [...]
A microscope is focused on a mark on a piece of paper and then a slab of glass of thickness 3 cm and refractive index 1.5 is placed over the mark. How should the microscope be moved to get the mark in focus again ?
20
Aug
A microscope is focused on a mark on a piece of paper and then a slab of glass of thickness 3 cm and refractive index 1.5 is placed over the mark. How should the microscope be moved to get the mark in focus again ? In total internal reflection when the angle of incidence is [...]
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 (see figure). How fast is the light traveling in the liquid?
20
Aug
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 (see figure). How fast is the light traveling in the liquid? In total internal reflection when the angle of incidence [...]
The frequency of a light wave in a material is 2 × 10¹⁴ Hz and wavelength is 5000 Å. The refractive index of material will be
20
Aug
The frequency of a light wave in a material is 2 × 10¹⁴ Hz and wavelength is 5000 Å. The refractive index of material will be In total internal reflection when the angle of incidence is equal to the critical angle for the pair of medium in contact what will be angle of refraction? August [...]
An air bubble in a glass slab with refractive index 1.5 (near normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness (in cm) of the slab is
20
Aug
An air bubble in a glass slab with refractive index 1.5 (near normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness (in cm) of the slab is In total internal reflection when the angle of incidence is equal to the critical [...]
In total internal reflection when the angle of incidence is equal to the critical angle for the pair of medium in contact, what will be angle of refraction?
20
Aug
In total internal reflection when the angle of incidence is equal to the critical angle for the pair of medium in contact, what will be angle of refraction? In total internal reflection when the angle of incidence is equal to the critical angle for the pair of medium in contact what will be angle of [...]