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प्रश्न
State two uses of ultraviolet radiation.
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उत्तर
(i) In producing vitamin D in plants.
(ii) For sterilizing purposes.
संबंधित प्रश्न
A beam of white light is shone onto a glass prism. The light cannot be:
(a) deviated
(b) dispersed
(c) focused
(d) refracted
Which of the following colour of white light has the least wavelength?
(a) red
(b) orange
(c) violet
(d) blue
A glass prism is able to produce the spectrum when white light passes through it, but a glass slab doesn’t produce any spectrum. Explain why it is so.
A wave has wavelength 50Å of State the speed in vacuum.
Answer the following:
What do you mean by dispersion? Name the different colours of light in the proper sequence in the spectrum of light.
A student has to trace the path of a ray of light through a glass prism. List four precautions he should observe for better results.
Draw a neat and labelled diagram for dispersion of light.
Curved mirrors have surfaces that are spherical, cylindrical, parabolic, and ellipsoid.
The angle of deviation through a prism is minimum when
- Incident rays and emergent rays are symmetric to the prism.
- The refracted ray inside the prism becomes parallel to its base.
- The angle of incidence is equal to that of the angle of emergence.
- When the angle of emergence has doubled the angle of incidence.
Choose the correct answer from the options given below:
Make a rainbow
Try to make your own rainbow. You can try this project in the morning or in the evening. Stand with your back towards the Sun. Take a hosepipe or a water pipe used in the garden. Make a fine spray in front of you. You can see different colours of rainbow in the spray.
