Physics
The figure given below shows the experimental set up for the determination of focal length of a lens using a plane mirror.
(a) Draw two rays from the point O of the object to show the formation of image I at O itself.
(b) What is the size of the image I?
(c) A convex lens of short focal length is used in which optical instrument?
(d) The focal length of a convex lens is 25 cm. Express its power with sign.
Related Questions
Jatin puts a pencil into a glass container having water and is surprised to see the pencil in a different state.
(a) What change is observed in the appearance of the pencil?
(b) What is the reason for this change?
(c) Classify the following as a real or virtual image:
The image of a candle flame formed on a screen by a convex lens.The adjacent diagram represents a glass slab of refractive index 1.5. If PA, PB, PC and PD represent the rays of light from a point P at the bottom of the block, draw the approximate directions of these rays as they emerge out of the glass slab. (sin 42° = 2/3)
A lens of focal length 15 cm forms an erect image three times the size of the object on a screen.
(a) What kind of lens is this?
(b) Find the position of the object from the lens.
(c) Find the position of the screen from the lens.
The diagram given below shows a ray of blue, yellow and red light incident on one face of a prism.
(a) Complete the diagram to show the effect of the prism on the ray of light and to show what is seen on the screen.
(b) A slit is placed in between the prism and the screen to pass yellow light only. What will be your observation on the screen ?
(c) What conclusion do you draw from the observation in part (ii) above ?