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
If the earth did not have atmosphere, would its average surface temperature be higher or lower than what it is now? Explain.
To which part of the electromagnetic spectrum does a wave of frequency 5 × 1011 Hz belong?
If the earth did not have an atmosphere, would its average surface temperature be higher or lower than what it is now?
A wave has a wavelength of 10-3 nm. Name the wave.
Name the waves used for taking photographs in dark.
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 scientist who discovered Microwaves
The frequency of e. m waves which is best suited .to observed of radius 3 × 10–4 his of the order of
Identify the part of the electromagnetic spectrum which:
- produces the heating effect.
- is absorbed by the ozone layer in the atmosphere.
- is used for studying crystal structure.
Write any one method of the production of each of the above radiations.
