Physics
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 ?
Answer
(a) Below diagram shows the effect of the prism on the beam and the spectrum seen on the screen :
(b) When a slit is placed in between the prism and the screen to pass only the light of yellow colour then only yellow light is observed on the screen because the slit blocks other colours (blue and red).
(c) From above experiment we can conclude that the prism does not produce colours, but it only splits the various colours present in the light incident on it.
Related Questions
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.
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.
In the figure given below, a ray of light PQ is incident normally on the face AB of an equilateral glass prism. Complete the ray diagram showing its emergence into air after passing through the prism. Take critical angle for glass = 42°
(a) Write the angles of incidence at the faces AB and AC of the prism.
(b) Name the phenomenon suffered by the ray of light at the face AB, AC and BC of the prism respectively.
A uniform metre scale is in equilibrium as shown in the diagram :
(i) Calculate the weight of the metre scale.
(ii) Which of the following options is correct to keep the ruler in equilibrium when 40 gf wt is shifted to 0 cm mark?
F is shifted towards 0 cm
or
F is shifted towards 100 cm.