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Question
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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Solution
RELATED QUESTIONS
Explain the following term related to spherical lenses: focal length
An image that cannot be obtained on a screen is called ______.
What is a virtual image?
Which type of mirror can form a real image?
Define Radius of curvature of the spherical mirror
Name the kind of mirror used to obtain
(a) a real and enlarged image
(b) a virtual and enlarged image
(c) a real and diminished image, and
(d) a virtual and diminished image.
An optical device has been given to a student and he determines its focal length by focusing the image of the sun on a screen placed 24 cm from the device on the same side as the sun. Select the correct statement about the device.
(A) Convex mirror of focal length 12 cm
(B) Convex lens of focal length 24 cm
(C) Concave mirror of focal length 24 cm
(D) Convex lens of focal length 12 cm
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.
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Write two more characteristics of the image.
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State two uses of a concave mirror.
A real and enlarged image can be obtained by using a
A concave mirror forms a virtual image of size twice that of the object placed at a distance 5 cm from it.
Find : (a) the focal length of the mirror (b) position of image
An object of length 4 cm is placed in front of a concave mirror at distance 30 cm. The focal length of mirror is 15 cm.
- Where will the image form?
- What will be the length of image?
An object of height 2 cm is placed at a distance of 20 cm in front of a concave mirror of a focal length of 12 cm. Find the position, size, and nature of the image.
Define the following term in relation to concave mirror.
Principal focus
Complete the following diagrams shown in the following figures by drawing the reflected rays.
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
Geometric centre of the spherical mirror is ______.
