Question 15 Marks
Write short notes on
(a) Infrared radiation
(b) Ultraviolet radiation
(c) Gamma radiation
(a) Infrared radiation
(b) Ultraviolet radiation
(c) Gamma radiation
Answer
View full question & answer→(a) Infrared radiation:
It is produced from hot bodies (also known as heat waves) and also when the molecules undergo rotational and vibrational transitions. The wavelength range is $8 \times 10^{-7} m$ to $5 \times 10^3 m$ and the frequency range is $4 \times 10^{14} Hz$ to $6 \times 10^{10} Hz$. It provides electrical energy to satellites by means of solar cells. It is used to produce dehydrated fruits, in green houses to keep the plants warm, heat therapy for muscular pain or sprain, TV remote as a signal carrier, to look through haze fog or mist, and used in night vision or infrared photography.
(b) Ultraviolet radiation:
It is produced by Sun, arc and ionized gases. The wavelength range is $6 \times 10^{-10}$ $m$ to $4 \times 10^{-7} m$ and the frequency range is $5 \times 10^{17} Hz$ to $7 \times 10^{14} Hz$. It has less penetrating power. It can be absorbed by atmospheric ozone and harmful to the human body. It is used to destroy bacteria, sterilizing the surgical instruments, burglar alarm, detect the invisible writing, finger prints and also in the study of molecular structure.
(c) Gamma rays:
It is produced by transitions of atomic nuclei and decay of certain elementary particles. They produce chemical reactions on photographic plates, fluorescence, ionization, diffraction. The wavelength range is $1 \times 10^{-14} m$ to $1 x$ $10^{-10} m$ and frequency range are $3 \times 10^{22} Hz$ to $3 \times 10^{18} Hz$. Gamma rays have high penetrating power than X-rays and ultraviolet radiations; it has no charge but harmful to human body. Gamma rays provide information about the structure of atomic nuclei. It is used in radio therapy for the treatment of cancer and tumour, in the food industry to kill pathogenic microorganisms.
It is produced from hot bodies (also known as heat waves) and also when the molecules undergo rotational and vibrational transitions. The wavelength range is $8 \times 10^{-7} m$ to $5 \times 10^3 m$ and the frequency range is $4 \times 10^{14} Hz$ to $6 \times 10^{10} Hz$. It provides electrical energy to satellites by means of solar cells. It is used to produce dehydrated fruits, in green houses to keep the plants warm, heat therapy for muscular pain or sprain, TV remote as a signal carrier, to look through haze fog or mist, and used in night vision or infrared photography.
(b) Ultraviolet radiation:
It is produced by Sun, arc and ionized gases. The wavelength range is $6 \times 10^{-10}$ $m$ to $4 \times 10^{-7} m$ and the frequency range is $5 \times 10^{17} Hz$ to $7 \times 10^{14} Hz$. It has less penetrating power. It can be absorbed by atmospheric ozone and harmful to the human body. It is used to destroy bacteria, sterilizing the surgical instruments, burglar alarm, detect the invisible writing, finger prints and also in the study of molecular structure.
(c) Gamma rays:
It is produced by transitions of atomic nuclei and decay of certain elementary particles. They produce chemical reactions on photographic plates, fluorescence, ionization, diffraction. The wavelength range is $1 \times 10^{-14} m$ to $1 x$ $10^{-10} m$ and frequency range are $3 \times 10^{22} Hz$ to $3 \times 10^{18} Hz$. Gamma rays have high penetrating power than X-rays and ultraviolet radiations; it has no charge but harmful to human body. Gamma rays provide information about the structure of atomic nuclei. It is used in radio therapy for the treatment of cancer and tumour, in the food industry to kill pathogenic microorganisms.