Advertisements
Advertisements
प्रश्न
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.
Advertisements
उत्तर
For a convex mirror, the focal length (f) is positive.
∴ f > 0
When the object is placed on the left side of the mirror, the object distance (u) is negative,
∴ u < 0
For image distance v, we have the mirror formula:
`1/"v" + 1/"u" = 1/"f"`
`1/"v" = 1/"f" - 1/"u"`
But we have u < 0
∴ `1/"v" > 1/"f"`
v < f
Hence, the image formed is diminished and is located between the focus (f) and the pole.
APPEARS IN
संबंधित 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.
Give two reasons to explain why a reflecting telescope is preferred over a refracting telescope.
Use the mirror equation to deduce that an object placed between the pole and focus of a concave mirror produces a virtual and enlarged image.
Using mirror formula, explain why does a convex mirror always produce a virtual image.
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
Use the mirror equation to show that an object placed between f and 2f of a concave mirror forms an image beyond 2f.
Mark the correct options.
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 small object is placed at the centre of the bottom of a cylindrical vessel of radius 3 cm and height 4 cm filled completely with water. Consider the ray leaving the vessel through a corner. Suppose this ray and the ray along the axis of the vessel are used to trace the image. Find the apparent depth of the image and the ratio of real depth to the apparent depth under the assumptions taken. Refractive index of water = 1.33.
Find the angle of deviation suffered by the light ray shown in figure. The refractive index μ = 1.5 for the prism material.

Write any one use for each of the following mirrors :
(a) Convex
(b) Concave
The figure below shows the positions of a point object O, two lenses, a plane mirror and the final image I which coincides with the object. The focal length of the convex lens is 20 cm. Calculate the focal length of the concave lens.

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.
Car B overtakes car A at a relative speed of 40 ms-1. How fast will the image of car B appear to move in the mirror of focal length 10 cm fitted in car A, when car B is 1.9 m away from car A?
When a clock is viewed in a mirror, the needles exhibit a time which appears to be 8:20. Then the actual time will be:
