Advertisements
Advertisements
प्रश्न
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.
Advertisements
उत्तर
Initially, the screen was placed beyond the focus to capture the image of the candle flame placed at a finite distance from the mirror. So, in order to capture a bright image of the Sun (at infinity) on the screen, the student should move the mirror towards the screen.
Hence, the correct option is B.
APPEARS IN
संबंधित प्रश्न
What is the relation between the focal length and radius of curvature of a spherical mirror (concave mirror of convex mirror)? Calculate the focal length of a spherical mirror whose radius of curvature is 25 cm.
A concave lens produces an image 20 cm from the lens of an object placed 30 cm from the lens. The focal length of the lens is:
(a) 50 cm
(b) 40 cm
(c) 60 cm
(d) 30 cm
Name the mirrors shown in Figure (a) and (b).
State the kind of mirror used
(a) By a dentist,
(b) As a search-light reflector.
The radius of curvature of a convex mirror is 40 cm. Find its focal length.
The magnification for a mirror is -3. How are u and v related?
An object forms a virtual image which is 1/8th of the size of the object. If the object is placed at a distance of 40 cm from the convex mirror, calculate:
- the position of the image
- the focal length of the convex mirror.
Define the term Centre of curvature.
An object is placed at a distance of 0.25 m
in front of a plane mirror. The distance between the object and image will be ______.
What is the focal length (f) of a mirror?
