Advertisements
Advertisements
प्रश्न
How will you investigate the existence of the radiation beyond the red and violet extremes of the spectrum?
How will you investigate the existence of electromagnetic radiation beyond the red and violet extremes of the spectrum? Explain in detail.
Advertisements
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.
APPEARS IN
संबंधित प्रश्न
Use the formula λm T= 0.29 cm K to obtain the characteristic temperature ranges for different parts of the electromagnetic spectrum. What do the numbers that you obtain tell you?
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?
(a) Give a list of at least five radiations, in order of their increasing frequencies, which make up the complete electromagnetic spectrum.
(b) Which of the radiation mentioned by you in part (a) has the highest penetrating power.
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.
Why is exposure to X-rays injurious to health but not exposure to visible light, when both are electromagnetic waves?
The Kα and Kβ X-rays of molybdenum have wavelengths 0.71 A and 0.63 A respectively. Find the wavelength of Lα X-ray of molybdenum.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Answer briefly.
Why are microwaves used in radar?
A car is moving towards a high cliff. The car driver sounds a horn of frequency f. The reflected sound heard by the driver has a frequency 2f. If v be the velocity of sound, then the velocity of the car, in the same velocity units, will be:
The half-value thickness of an absorber is defined as the thickness that will reduce exponentially the intensity of a beam of particles by a factor of 2. The half-value thickness in (µm) for lead assuming X-ray beam of wavelength 20 pm, µ = 50 cm-1 for X-rays in lead at wavelength λ = 20 pm, is ______ µm.
