Optics Answers

A far sighted person has his near point 50cm,find the power of lens he should use to see at 25cm, clearlly

Two plane mirrors are separated by an angle of 130°, if a ray of light strikes the first mirror at an angle of incidence of 70°. Calculate the angle of reflection at which the ray leaves the second mirror.

An object is placed at a distance of 100cm from a convex mirror, the magnification produced is half. Where the object should be placed to a magnification of 1/4

An object 7m high is placed 15cm from a concave spherical mirror of radius 245cm .describe the image

Monochromatic light of wavelength 630 nm is incident on a slit of width 16 µm. A diffraction pattern is produced on a screen 2.0 m away from the slit.
What is the width of the central peak in the diffraction pattern produced on the screen? (to 2 s.f and in cm)

Draw the basic configuration of typical optical fibre communication.

What is a step - index fibre ? Obtain an expression for the angle of incidence beyond which light will get refracted into the cladding material. What will happen if the refractive index of the cladding is higher than that of the core ?

An ordinary source emits light at 103k. Show that in this case, spontaneous emission will dominate over stimulated emission.

For interference in thin films, obtain the condition of constructive and destructive
interference between reflected light waves.

The diffraction bands are of variable thickness,
whereas interference bands are equidistant'.
Discuss the validity of this statement with
reference to the diffraction pattern of a straight
edge.