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प्रश्न
The shiny outer surface of a hollow sphere of aluminium of radius 50 cm is to be used as a mirror:
What will be the focal length of this mirror?
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उत्तर
संबंधित प्रश्न
A student focused the Sun rays using an optical device 'X' on a screen S as shown.
From this it may be concluded that the device 'X' is a (select the correct option)
(A) Convex lens of focal length 10 cm.
(B) Convex lens of radius of curvature 20 cm.
(C) Convex lens of focal length 20 cm.
(D) Concave mirror of focal length 20 cm.
Explain the following term related to spherical lenses:- principal focus
Name the spherical mirror which has:
(a) virtual principal focus.
(b) real principal focus.
A lens forms a real image 3 cm high of an object 1 cm high. If the separation of object and image is 15 cm, find the focal length of the lens.
What do you mean by the term dispersion?
A student obtained on a screen the sharp image of a candle flame placed at the farther end of laboratory table using a concave mirror. For getting better value of focal length of the mirror, the teacher suggested to him to focus the sun. What should the student do?
(A) Should move the mirror away from the screen.
(B) Should move the mirror towards the screen.
(C) Should move the mirror and screen both towards the sun.
(D) Should move only the screen towards the sun.
Figure shows a concave mirror with its pole at P, focus F and centre of curvature C. Draw ray diagram to show the formation of image of an object OA.
Answer the following question.
Write the modification in the curvature of the eye lens which enables us to see the nearby objects clearly?
The boxes in figure (a, b, c) represent mirrors; insert a mirror which will reflect the incident ray as shown in the diagram.
Complete the following diagrams shown in the following figures by drawing the reflected rays.
A concave mirror can be used to produce a parallel beam of light. Draw a ray to illustrate this.
The following Figure shows a concave mirror MM' on which a ray of light incident from a point P gets reflected to meet the principle axis at O.
(a) Find, by construction, the position of the centre of curvature of the concave mirror.
(b) Write down the value for the radius of curvature of the mirror.
(c) Calculate the focal length of the mirror.
(d ) Which relation is used in deducing the focal length from the radius of curvature?
If the focal length of a spherical mirror is 10 cm, what is the value of its radius of curvature?
The spherical mirror used in a beauty parlour as make-up mirror is _______.
The distance from the center of curvature of the mirror to the pole is called the focal length of the mirror.
How tall does a mirror have to be to fit an entire person’s body?
