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संबंधित प्रश्न
A student obtained a sharp image of a burning candle, placed at the farther end of a laboratory table, on a screen using a concave mirror. For getting better value of focal length of the mirror, the subject teacher suggested him for focusing a well illuminated distant object. What should the student do?
(A) He should move the mirror away from the screen.
(B) He should move the mirror slightly towards the screen.
(C) He should move the mirror as well as the screen towards the newly selected object.
(D) He should move only the screen towards the newly selected object.
In each case (a) and (b), draw reflected rays for the given incident rays and mark focus by the symbol F.
Define the term Normal.
An object 10 cm high is placed at a distance of 20 cm in front of a spherical mirror of focal length 25 cm. By scale drawing find the nature, position, and magnification of the image in the following case:
Concave mirror
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?
Numerical problem.
The radius of curvature of a spherical mirror is 25 cm. Find its focal length.
A ray of light is incident towards a plane mirror at an angle of 30° with the mirror surface. What will be the angle of reflection?
What is “aperture”?
A converging lens of focal length f is placed at a distance 0.3 m from an object to produce an image on a screen 0.9 m from the lens. With the object and the screen in the same positions, an image of the object could also be produced on the screen by placing a converging lens of focal length.
In normal adjustment, for a refracting telescope, the distance between objective and eye piece is 30 cm. The focal length of the objective, when the angular magnification of the telescope is 2, will be ______.
