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प्रश्न
If the radius of curvature of a concave mirror is 20 cm, its focal length is:
पर्याय
10 cm
20 cm
40 cm
80 cm
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उत्तर
10 cm
APPEARS IN
संबंधित प्रश्न
Draw ray diagrams to show the principal focus of a concave mirror.
Study the following diagram and select the correct statement about the device 'X' :
(A) Device 'X' is a concave mirror of radius of curvature 12 cm
(B) Device 'X' is a concave mirror of focal length 6 cm
(C) Device 'X' is a concave mirror of focal length 12 cm
(D) Device 'X' is a convex of mirror of focal length 12 cm
List four specific characteristics of the images of the objects formed by convex mirrors.
Three students A, B and C focussed a distant building on a screen with the help of a concave mirror. To determine focal length of the concave mirror they measured the distances as given below:
Student A : From mirror to the screen
Student B : From building to the screen
Student C : From building to the mirror
Who measured the focal length correctly ;
(a) Only A
(b) Only B
(c) A and B
(d) B and C
Define the principal focus of a concave mirror.
Copy this figure in your answer book and show the direction of the light ray after reflection:
Draw a ray diagram to show the formation of the image of an object placed beyond the centre of curvature of a concave mirror. State the position, size and nature of the image.
Suppose you have three concave mirrors A, B and C of focal lengths 10 cm, 15 cm and 20 cm. For each concave mirror you perform the experiment of image formation for three values of object distance of 10 cm, 20 cm and 30 cm. Giving reason answer the following:
(a) For the three object distances, identify the mirror/mirrors which will form an image of magnification – 1.
(b) Out of the three mirrors identify the mirror which would be preferred to be used for shaving purposes/makeup.
(c) For the mirror B draw ray diagram for image formation for object distances 10 cm and 20 cm.
Why are concave mirrors used in solar devices?
To obtain an image twice the size of the object, between which two points related to a concave mirror should an object be placed?
