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प्रश्न
Write a short note on the visible spectrum.
उत्तर
Visible spectrum is produced by incandescent bodies and also it is radiated by excited atoms in gases. The wavelength range is 4 x 10-7 m to 7 x 10-7 m and the frequency range is 7 x 1014 Hz to 4 x 1014Hz. It obeys the laws of reflection, refraction, interference, diffraction, polarization, photoelectric effect, and photographic action. It can be used to study the structure of molecules, the arrangement of electrons in external shells of atoms, and the sensation of our eyes.
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संबंधित प्रश्न
When Sunita, a class XII student, came to know that her parents are planning to rent out the top floor of their house to a mobile company she protested. She tried hard to convince her parents that this move would be a health hazard.
Ultimately her parents agreed :
(1) In what way can the setting up of transmission tower by a mobile company in a residential colony prove to be injurious to health?
(2) By objecting to this move of her parents, what value did Sunita display?
(3) Estimate the range of e.m. waves which can be transmitted by an antenna of height 20 m. (Given radius of the earth = 6400 km)
How does oscillating charge produce electromagnetic waves?
Arrange the following electromagnetic waves in order of increasing frequency:
ϒ-rays, microwaves, infrared rays and ultraviolet rays.
How are the magnitudes of the electric and magnetic fields related to velocity of the em wave?
A wire carries an alternating current i = i0 sin ωt. Is there an electric field in the vicinity of the wire?
Write notes on Gauss' law in magnetism.
Give two uses of UV radiation.
A linearly polarized electromagnetic wave given as E = Eoî cos (kz – ωt) is incident normally on a perfectly reflecting infinite wall at z = a. Assuming that the material of the wall is optically inactive, the reflected wave will be given as ______.
For an electromagnetic wave travelling in free space, the relation between average energy densities due to electric (Ue) and magnetic (Um) fields is ______.
A plane electromagnetic wave travels in free space along the x-direction. The electric field component of the wave at a particular point of space and time is E = 6 Vm-1 along the y-direction. Its corresponding magnetic field component, B would be ______.
