Advertisements
Advertisements
Question
Select the correct option:
A concave mirror is made by cutting a portion of a hollow glass sphere of radius 30 cm. The focal length of the concave mirror is:
Options
24 cm
12 cm
15 cm
60 cm
Solution
15 cm
Explanation:
Radius of curvature = R = 30 cm
Focal length of concave mirror f = `"R"/2`
f = `30/2 = 15` cm
APPEARS IN
RELATED QUESTIONS
Explain the following term related to spherical lenses:- aperture
Find out the letters of English alphabet or any other language known to you in which the image formed in a plane mirror appears exactly like the letter itself. Discuss your findings.
Define the terms pole, principal axis and centre of curvature with reference to a spherical mirror.
The diagram below in Figure, shows a convex mirror. C is its centre of curvature and F is its focus. (i) Draw two rays from A and hence locate the position of image of object OA. Label the image IB. (ii) State three characteristics of the image.
AB is the object, A'B' is the image, and MM' is the position of the mirror. Complete the ray diagram showing the formation of the image and find the focal length of the mirror.
The spherical mirror used in a beauty parlour as make-up mirror is _______.
The radius of curvature of a spherical mirror is 18 cm. What is the focal length of this mirror?
The minimum length of the mirror required to see the full image of the person is half ‘ of his height.
How tall does a mirror have to be to fit an entire person’s body?