Optics Answers

diameter of a plano convex lens is 6cm and thickness at the centre is 3mm.if speed of light in material of lens os 2*100000000m/s,the focal length of the lens is?

Alpha-Centari, is located at a distance of 4.5 light years. What is the diameter of a reflecting telescope, placed in Earths orbit, observed in visible light at 550nm, in order to resolve:a-A planet orbiting its star at the same distance as earth is from the sun.b- A sun sized star. c- Earth sized planet?

How far should an object be placed from a concave spherical mirror of radius
38cm to form a real image of one-ninth its size?

If light travels in a straight line, why a rainbow appears curved?

Diffraction will be best if the gap is equal to the wave length, but what
will be if the gap is smaller than the wave length?

A spherical concave lens has a focal length of 20 cm, and an object is placed 15 cm from the lens. What are the image distance and the image characteristics?

if focal length of convex lens is f and it is cut into two equal part what is focal length of each part?

define 'phase' and 'phase difference'.

at an instant a watch shows time 2:35 when seen through a mirror,what time will be appeared?

A ray of light strikes a horizontal plane mirror at an angle of 45. At what angle should a second plane mirror be placed in order that the reflected ray finally be reflected horizontal?