Advertisements
Advertisements
Question
What role dose infra-red radiation play in maintain the Earth’s warmth
Solution
Visible light from the atmosphere is absorbed by the Earth’s surface and radiated as infrared radiation which gets trapped by greenhouse gases such as carbon dioxide and water vapour. This is how infrared radiation also plays an important role in maintaining the Earth’s warmth
APPEARS IN
RELATED QUESTIONS
The terminology of different parts of the electromagnetic spectrum is given in the text. Use the formula E = hv (for energy of a quantum of radiation: photon) and obtain the photon energy in units of eV for different parts of the electromagnetic spectrum. In what way are the different scales of photon energies that you obtain related to the sources of electromagnetic radiation?
The X-ray beam emerging from an X-ray tube
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.
Name the radiation which can be detected by thermopile.
To which regions of the electromagnetic spectrum do the following wavelengths belong:
(a) 250 nm
(b) 1500 nm
Identify the part of the electromagnetic spectrum used in
(i) radar and
(ii) eye surgery. Write their frequency range.
Answer briefly.
Give two uses of radio waves.
Answer briefly.
What is a carrier wave?
Below is an incomplete table showing the arrangement of electromagnetic spectrum in the increasing order of their wavelength. Complete the table:
Gamma ray | X - ray | UV rays | Visible rays | Infrared | A | Radio waves |
- Identify the radiation A.
- Name the radiation used to detect fracture in bones.
- Name one property common to both A and Radio waves.