Advertisements
Advertisements
Question
Explain the following term related to spherical lenses: focal length
Advertisements
Solution
Focal Length:-
The focal length of a lens is the distance between optical centre and principal focus of the lens.
RELATED QUESTIONS
What is the name of the phenomenon in which the right side of an object appears to be the left side of the image in a plane mirror?
Draw separate diagram for the formation of virtual image of an object by a concave mirror.
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.
Figure shows a concave mirror with its pole at P, focus F and centre of curvature C. Draw ray diagram to show the formation of image of an object OA.
For what position of object, the image formed by a concave mirror is magnified and erect?
State whether the image in part (a) is real or virtual?
State the position of object for which the image formed by a concave mirror is of same size.
Write two more characteristics of the image.
How is the focal length of a spherical mirror related to its radius of curvature?
Define the term principal focus in case of convex mirror. Draw a convex mirror and show its principal focus and focal length clearly.
