TEST NO. 9
MAXIMUM MARKS : 15
1. State essential condition for diffraction of light to occur.
(1)
2. What is the condition for first minimum in case of diffraction due to
(1)
single slit?
3. What should be the approximate slit size to observe diffraction with it?
(1)
4. In a single slit diffraction experiment, the width of the slit is made double
(1)
the original width. How does this affect the size and intensity of the
central diffraction band?
5. Yellow light is used in a single slit diffraction experiment with slit width
(1)
of 0.6 mm. If yellow light is replaced by X-rays, how will the diffraction
pattern be affected?
6. What change will you observe in diffraction pattern of single slit,
(1)
when monochromatic light is replaced by a source of white light?
7. How is the width of central maxima affected on increasing the
i)
Wavelength of light used
ii)
Width of the slit
iii)
What happens to the width of central maxima if the whole
(3)
apparatus is immersed in water and why?
8. State with reason, how would the linear width of central maxima
(3)
change when
i)
Slit width is decreased
ii)
Distance between slit and screen is increased
iii)
Light of smaller visible wavelength is used?
Justify your answer in each case
9. Give some points of difference between interference and diffraction.
(3)