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प्रश्न
If the earth did not have an atmosphere, would its average surface temperature be higher or lower than what it is now?
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उत्तर
In the absence of an atmosphere, there would be no greenhouse effect on the surface of the Earth. As a result, the temperature of the Earth would decrease rapidly, making it chilly and difficult for humans to survive.
संबंधित प्रश्न
If the earth did not have atmosphere, would its average surface temperature be higher or lower than what it is now? Explain.
What is the range of the wavelength of the following electromagnetic waves?
(A) Radio waves.
State the approximate range of wavelength associated with infrared rays.
Name the radiations of wavelength just longer than 8 × 10-7m.
Name three properties of ultraviolet radiations which are similar to visible light.
An electromagnetic wave has a frequency of 500 MHz and a wavelength of 60 cm Calculate the velocity of the wave.
In a Coolidge tube, electrons strike the target and stop inside it. Does the target get more and more negatively charged as time passes?
Can X-rays be used for photoelectric effect?
Moseley's Law for characteristic X-ray is √v = a(Z − b). Here,
The wavelength of Kα X-ray of tungsten is 21.3 pm. It takes 11.3 keV to knock out an electron from the L shell of a tungsten atom. What should be the minimum accelerating voltage across an X-ray tube having tungsten target which allows production of Kα X-ray?
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
The energy of a silver atom with a vacancy in K shell is 25.31 keV, in L shell is 3.56 keV and in M shell is 0.530 keV higher than the energy of the atom with no vacancy. Find the frequency of Kα, Kβ and Lα X-rays of silver.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
When 40 kV is applied across an X-ray tube, X-ray is obtained with a maximum frequency of 9.7 × 1018 Hz. Calculate the value of Planck constant from these data.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Continuous X-rays are made to strike a tissue paper soaked with polluted water. The incoming X-rays excite the atoms of the sample by knocking out the electrons from the inner shells. Characteristic X-rays are analysed and the intensity is plotted against the wavelength. Assuming that only Kα intensities are detected, list the elements present in the sample from the plot. Use Moseley's equation v − (25 × 1014Hz)(Z − 1)2.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
| 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 of the electromagnetic spectrum which is used for the following:
For taking photographs of the sky during the night and foggy conditions . Give the frequency range
Find the photon energy in units of ev for electromagnetic wave if waves length 40 m. Given h = 6.63 × 10–34 J.
Photons of an electromagnetic radiation has an energy 11 keV each. To which region of electromagnetic spectrum does it belong?
Identify the electromagnetic wave whose wavelength range is from about 10-3 m to about 10-1 m. Write one use of this.
Assertion (A): Ultraviolet radiations is scattered more as compared to the microwave radiations.
Reason (R): Wavelength of ultraviolet radiation is more than the wavelength of microwave radiation.
Name one radiation having the wavelength longer than the wavelength of these radiations.
