Advertisements
Advertisements
प्रश्न
The small ozone layer on top of the stratosphere is crucial for human survival. Why?
Advertisements
उत्तर
The small ozone layer on the top of the atmosphere is crucial for human survival because it absorbs harmful ultraviolet radiations present in sunlight and prevents it from reaching the Earth’s surface.
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.
Name two electromagnetic waves of frequency smaller than that of violet light. State one use of each.
Give one use of microwaves.
Give one use of gamma rays.
Can a hydrogen atom emit characteristic X-rays?
If the current in the circuit for heating the filament is increased, the cutoff wavelength
For harder X-rays,
(a) the wavelength is higher
(b) the intensity is higher
(c) the frequency is higher
(d) the photon energy is higher.
Iron emits Kα X-ray of energy 6.4 keV. Calculate the times taken by an iron Kα photon to cross through a distance of 3 km.
(Use Planck constant h = 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
The short-wavelength limit shifts by 26 pm when the operating voltage in an X-ray tube is increased to 1.5 times the original value. What was the original value of the operating voltage?
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Name the scientist who discovered Infra-red waves
| Gamma rays | D | C | Visible light | B | A |
The above table shows different parts of the electromagnetic spectrum.
(a) Identify the parts of the spectrum marked as A, B, C and D.
(b) Which of the radiations A or B has the higher frequency?
(c) State two properties which are common to all parts of the electromagnetic spectrum.
(d) Name one source of each of the radiation of electromagnetic spectrum.
(e) Name one detector for each of the radiation.
(f) Name one use of each of the radiation.
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
State two properties of infrared radiations which differ from visible light.
Give one use of electromagnetic radiation in Ultraviolet radiation.
Name the radiations used for the detection of fracture in bones.
Following QN ∴ 14, the radiation force on the roof will be
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.
Name one radiation having the wavelength longer than the wavelength of these radiations.
Name the electromagnetic radiation that has been used in obtaining the image below.
