Optics Answers

Monochromatic light is used to illuminate a pair of narrow slits 0.3 mm apart and the interference pattern is observed on a source 0.91 mm away. The second dark band appears 3.0 mm from the centre. What is the wavelength in metres?

A number of images of a candle flame are seen in a thick mirror silvered at the back. The bright image is the second image. Why?

The range of visible light is 4000A° to 7000A°. Will photoelectrons be emitted by a copper surface of work function 4.4 eV, when illuminated by visible light? Give the mathematical prove of your answer?

DO MATERIALS ALWAYS HAVE THE SAME COLOUR WHETHER VIEWED BY REFLECTED LIGHT OR THROUGH TRANSMITTED LIGHT?

1)why when water passes a log in water a smooth area of water is created behind the log but when the same wave passes a blade of grass there is no smooth area of water created?
a. length of water waves is short in comparison to the size of the grass
b. length of water waves is short in comparison to the size of the log
c. shadow area is created by the blade of grass but no shadow is created by the log

2)an interference pattern is produced when
a a pattern of light &dark fringes id produced
b both constructive & destructive interference occur
c diffraction occurs
d. all above

3) as sunlight on a bubble, one wave length of blue light is reflected from the inner surface of the soap film another wavelength of Blue light if reflected from the outer surface as the waves superimpose they are one half wave length out phase.. what will we see on that spot off film?
a.yellow
b. very deep blue
c. no color
d. red

if green light is scattered more often
than any other frequency of light what…‡
color would the sky be
at noon?

i would like to know if a laser beam has a low frequency or a high frequency ?