Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Other visible light hazards : Ordinary, visible light can present a hazard under certain conditions. You can burn paper by focussing the sun's rays using a small magnifying lens. The same effect can occur with the eye's lens on the back of the eyeball (the retina), and this usually happens when we are viewing an eclipse. The result can be total blindness or at least partial blindness. Similar dangers can occur when using daylight to illuminate a microscope slide.
The source of the danger is the sudden and intense illumination of a human eye by the sun. The accidents occur because it is difficult to ensure that a filter is going to absorb sufficient light to make it safe to view a sudden appearance of the sun, such as an eclipse, directly. The absorbent powers of a filter won't be instrument. discovered until it is too late, and the time-honoured method of using smoked glass is much unreliable. You can imagine how much worse the damage would be to the human eye if an eclipse was viewed through any optical instrument, e.g. binoculars, reflecting devices on microscopes, etc.
The only safe way to view an eclipse is to look at an image of the sun projected onto a screen. This means that a laboratory or classroom would have to be turned into a projection room, i.e. blacked out with a screen and an optical system need only be a 1 cm hole in a blind to a limit the required light and a plain mirror to direct the light onto the screen, Figure.
Figure: Safe way to view an eclipse
Temperature affects the _____ of sound waves !?
Decribe the factors which decide the broad area of scientific activity
What are all the planets in our solar system?
Model water wheels A meat skewer or a knitting needle can be used as an axle. An old typewriter ribbon- spool or a sticking plaster reel is useful as a basis for these improvis
Minerals: Our bones and teeth contain large amounts of calcium. An adult has a total of about 1 kg of calcium and a baby has about 30g in their bones. So, during the period o
Define the Sources of sound and their level of loudness Let us now have a look at Table, where the various sources of sound, their level of loudness and its comparison to the f
Advantages of water in chemical weathering Water is an essential factor of chemical weathering and when it contains dissolved salts and acids it is all the more effective. It
Holding water in a sieve Pour some oil over the wire mesh of a kitchen sieve and shake out the overload so that the holes are open. Cautiously pour water into the sieve from a
An aneroid barometer The corrugated rubber tube from a gas mask, or a cycle grip, can be used to make a model aneroid barometer. No huge accuracy is to be expected due to the m
what are alveoli?
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd