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प्रश्न
Name the subjective property of light related to its wavelength.
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उत्तर
(i) For blue light, approximate wavelength=4800 Å
(ii) For red light, approximate wavelength=8000 Å
संबंधित प्रश्न
Name the electromagnetic radiations used for (a) water purification, and (b) eye surgery.
State Moseley's law
Name two electromagnetic waves of frequency smaller than that of violet light. State one use of each.
Name the waves used for taking photographs in dark.
If the potential difference applied to the tube is doubled and the separation between the filament and the target is also doubled, the cutoff wavelength
X-ray from a Coolidge tube is incident on a thin aluminium foil. The intensity of the X-ray transmitted by the foil is found to be I0. The heating current is increased to increase the temperature of the filament. The intensity of the X-ray transmitted by the foil will be
(a) zero
(b) < I0
(c) I0
(d) > I0
Name the radiation which can be detected by thermopile.
Arrange the following electromagnetic radiation in the ascending order of their frequencies:
X-rays, microwaves, gamma rays, radio waves
Identify the electromagnetic wave whose wavelength range is from about 10-3 m to about 10-1 m. Write one use of this.
In an atom X, electrons absorb the energy from an external source. This energy “excites” the electrons from a lower-energy level to a higher-energy level around the nucleus of the atom. When electrons return to the ground state, they emit photons.
The figure below is the energy level diagram of atom X with three energy levels, E1 = 0.00eV, E2 = 1.78eV and E3 = 2.95eV. The ground state is considered 0 eV for reference. The transition of electrons takes place between levels E1 and E2.
- What wavelength of radiation is needed to excite the atom to energy level E2 from E1?
- Suppose the external source has a power of 100 W. What would be the rate of photon emission?
