Advertisements
Advertisements
प्रश्न
Identify the electromagnetic radiation and write its wavelength range, which is used to kill germs in water purified. Name the two sources of these radiations.
Advertisements
उत्तर
Radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, gamma rays, and cosmic rays provide the whole range (electromagnetic spectrum) in increasing frequency and decreasing wavelength order. The type of radiation and their frequency and wavelength ranges are as follows:
| Types of Radiation | Frequency Range (Hz) | Wavelength Range |
| Gamma-rays | 1020 - 1024 | < 10-12 m |
| X-rays | 1017 - 1020 | 1 nm - 1 pm |
| Ultraviolet | 1015 - 1017 | 400 nm - 1 nm |
| Visible | 4 × 1014 - 7.5 × 1014 | 750 nm - 400 nm |
| Near-infrared | 1 × 1014 - 4 × 1014 | 2.5 µm - 750 nm |
| Infrared | 1013 - 1014 | 25 µm - 2.5 µm |
| Microwaves | 3 × 1011 - 1013 | 1 mm - 25 µm |
| Radio waves | < 3 × 1011 | > 1 mm |
In water purifiers, ultraviolet light is utilised to kill bacteria. The sun is the most powerful source of UV radiation.
UV lamps, arc welding, and mercury vapour lamps are examples of man-made ultraviolet sources. Carbon, Xenon, and other arcs are some of the devices that release UV radiation.
APPEARS IN
संबंधित प्रश्न
Name the high energetic invisible electromagnetic waves which help in the study of the structure of crystals
What is the range of the wavelength of the following electromagnetic waves?
(a) Ultraviolet
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.
One of the following wavelengths is absent and the rest are present in the X-rays coming from a Coolidge tube. Which one is the absent wavelength?
X-ray incident on a material
(a) exerts a force on it
(b) transfers energy to it
(c) transfers momentum to it
(d) transfers impulse to it.
The Kα X-rays of aluminium (Z = 13) and zinc (Z = 30) have wavelengths 887 pm and 146 pm respectively. Use Moseley's law √v = a(Z − b) to find the wavelengths of the Kα X-ray of iron (Z = 26).
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
State the name and the range of wavelength of the invisible electromagnetic waves beyond the red end of the visible spectrum.
Answer briefly.
Does an ordinary electric lamp emit EM waves?
In uranium (Z = 92) the K absorption edge is 0.107 Å and the Kα line is 0.126 Å, and the wavelength of the L absorption edge is ______.
Name the electromagnetic radiation whose frequency is 10 Hz.
