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प्रश्न
How will you investigate the existence of the radiation beyond the red and violet extremes of the spectrum?
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उत्तर
If a blackened bulb thermometer is moved from the violet end towards the red end, first a steady rise in temperature is observed, but as the thermometer goes beyond the red end, there is a rapid rise in temperature. This shows the existence of some kind of radiation producing the heating effect beyond the red end of the spectrum.
If the radiations from the red end to the violet end are made to fall on the silver chloride solution, it almost remains unaffected beyond the violet end of the spectrum.
संबंधित प्रश्न
A plane electromagnetic wave travels in vacuum along z-direction. What can you say about the directions of its electric and magnetic field vectors? If the frequency of the wave is 30 MHz, what is its wavelength?
The wavelengths for the light of red and blue colours are roughly 7.8 × `10^7` m and 4.8 × `10^7` m respectively.
(a) Which colour has the greater speed in vacuum?
(b) Which colour has the greater speed in glass?
State the approximate range of wavelength associated with visible light.
Two waves A and B have wavelength 0.01 Å and 9000 Å respectively.
- Name the two waves.
- Compare the speeds of these waves when they travel in vacuum.
How are X-rays produced?
X-ray and visible light travel at the same speed in vacuum. Do they travel at the same speed in glass?
Characteristic X-rays may be used to identify the element from which they are being emitted. Can continuous X-rays be used for this purpose?
The electric current in an X-ray tube (from the target to the filament) operating at 40 kV is 10 mA. Assume that on an average, 1% of the total kinetic energy of the electron hitting hte target are converted into X-rays.
(a) What is the total power emitted as X-rays and (b) how much heat is produced in the target every second?
Heat at the rate of 200 W is produced in an X-ray tube operating at 20 kV. Find the current in the circuit. Assume that only a small fraction of the kinetic energy of electrons is converted into X-rays.
Name the radiation which can be detected by thermopile.
