A focal length of a lens is 10 cm. What is power of a lens in dioptre?
A focal length of a lens is 10 cm. What is power of a lens in dioptre?
Options
(a) 0.1 D (b) 10 D (c) 15 D (d) 1 D
Correct Answer:
10 […]
Questions
A luminous object is seperated from a screen by distance d. A convex lens
A luminous object is seperated from a screen by distance d. A convex lens is placed between the object and the screen such that it forms a distinct image on the screen. The maximum possible […]
Two lenses of power 15 D and -3 D are placed in contact.
Two lenses of power 15 D and -3 D are placed in contact. The focal length of the combinations is
Options
(a) 10 cm (b) 15 cm (c) 12 cm (d) 8.33 cm
The equiconvex lens has focal length f. If it is cut perpendicular to the principal
The equiconvex lens has focal length f. If it is cut perpendicular to the principal axis passing through optical centre, then focal length of each half is
Options
(a) f/2 (b) f (c) 3f/2 […]
In vacuum, to travel distance d, light takes time t and in medium to travel distance
In vacuum, to travel distance d, light takes time t and in medium to travel distance 5d, it takes time T. The critical angle of the medium is
Options
(a) sin⁻¹(5T/t) (b) sin⁻¹(5t/3T) (c) […]
An object placed at 20 cm in front of a concave mirror produces three times
An object placed at 20 cm in front of a concave mirror produces three times magnified real image. What is the focal length of the concave mirror?
Options
(a) 15 cm (b) 6.6 cm […]
To get three images of single object, one should have two plane mirrors at an angle of
To get three images of single object, one should have two plane mirrors at an angle of
Options
(a) 60⁰ (b) 90⁰ (c) 120⁰ (d) 30⁰
Correct Answer:
90⁰
Explanation:
Consider the diagram where […]
To measure the roughness of the surface of a material, which of the following microscope
To measure the roughness of the surface of a material, which of the following microscope is preferred for better result output?
Options
(a) Compound microscope (b) Electron microscope (c) Atomic force microscope (d) […]
A ray enters a glass sphere of refractive index μ=√3 at an angle of incidence of 60⁰
A ray enters a glass sphere of refractive index μ=√3 at an angle of incidence of 60⁰, a ray is reflected and refracted at the farther surface of the sphere. The angle between the reflected […]
The limiting angle of incidence for an optical ray that can be transmitted
The limiting angle of incidence for an optical ray that can be transmitted by an equilateral prism of refractive index μ=√7/3 is given by(angles can be assumed to be small, so that sine of the […]