Advertisements
Advertisements
प्रश्न
Calculate the distance of an object of height h from a concave mirror of radius of curvature 20 cm, so as to obtain a real image of magnification 2. Find the location of the image also.
Advertisements
उत्तर
Given: Radius of curvature of mirror = 20 cm
∴ Focal length of mirror, f = −10 cm
Since the image is real,
Magnification of image, m = −2
`m=-v/u`
`=>-2=-v/u`
`=>v=2u`
Using mirror formula,
`1/f=1/v+1/u=1/(2u)+1/u=3/(2u)`
`=>u=3/2 f=3/2xx(-10)=-15cm`
∴v=2u=−30 cm
Therefore, the distance of the object is 15 cm in front of the mirror and the position of the image is 30 cm in front of the mirror.
संबंधित प्रश्न
Use the mirror equation to show that a convex mirror always produces a virtual image independent of the location of the object.
Use the mirror equation to deduce that the virtual image produced by a convex mirror is always diminished in size and is located between the focus and the pole.
An object is kept on the principal axis of a concave mirror of focal length 10 cm. at a distance of 15
cm from its pole. The image formed by the mirror is:
(a) Virtual and magnified
(b) Virtual and diminished
(c) Real and magnified
(d) Real and diminished
Can a plane mirror ever form a real image?
The rays of different colours fail to converge at a point after going through a converging lens. This defect is called
A light ray falling at an angle of 45° with the surface of a clean slab of ice of thickness 1.00 m is refracted into it at an angle of 30°. Calculate the time taken by the light rays to cross the slab. Speed of light in vacuum = 3 × 108 m s−1.
A cylindrical vessel of diameter 12 cm contains 800π cm3 of water. A cylindrical glass piece of diameter 8.0 cm and height 8.0 cm is placed in the vessel. If the bottom of the vessel under the glass piece is seen by the paraxial rays (see figure), locate its image. The index of refraction of glass is 1.50 and that of water is 1.33.
A light ray is incident at an angle of 45° with the normal to a √2 cm thick plate (μ = 2.0). Find the shift in the path of the light as it emerges out from the plate.
For paraxial rays, show that the focal length of a spherical mirror is one-half of its radius of curvature.
A parallel beam of light is allowed to fall on a transparent spherical globe of diameter 30cm and refractive index 1.5. The distance from the centre of the globe at which the beam of light can converge is ______ mm.
