Advertisements
Advertisements
प्रश्न
Answer briefly.
Can we produce a pure electric or magnetic wave in space? Why?
Advertisements
उत्तर
No.
In vacuum, an electric field cannot directly induce another electric field so a “pure” electric field wave cannot exist and same can be said for a “pure” magnetic wave.
APPEARS IN
संबंधित प्रश्न
How are infrared waves produced?
What role dose infra-red radiation play in physical therapy?
A radio can tune in to any station in the 7.5 MHz to 12 MHz band. What is the corresponding wavelength band?
Name the phenomenon which shows the quantum nature of electromagnetic radiation.
A wave has wavelength 50 Å.
- Name the wave.
- State its speed in vacuum.
- State its one use.
Which radiation is used for satellite communication?
Name the rays or waves of highest frequency .
Name the waves produced by the changes in the nucleus of an atom.
How are X-rays produced?
Can Lα X-ray of one material have shorter wavelength than Kα X-ray of another?
Visible light passing through a circular hole forms a diffraction disc of radius 0.1 mm on a screen. If an X-ray is passed through the same setup, the radius of the diffraction disc will be
The Kβ X-rays from certain elements are given below. Draw a Moseley-type plot of √v versus Z for Kβ radiation.
| Element | Ne | P | Ca | Mn | Zn | Br |
| Energy (keV) | 0.858 | 2.14 | 4.02 | 6.51 | 9.57 | 13.3 |
Name the scientist who discovered Microwaves
Name the radiation which can be detected by thermopile.
Name the radiations used for the detection of fracture in bones.
What are the ultraviolet rays?
Answer briefly.
Give two uses of radio waves.
Answer briefly.
What is a carrier wave?
Name the e.m. waves which are suitable for radar systems used in aircraft navigation. Write the range of frequency of these waves.
For television broadcasting, the frequency employed is normally
Microwaves are electromagnetic waves with frequency in the range of.
Ozone layer above the earth's atmosphere will
Radio waves of constant amplitude can be generated with.
Give any two uses of infrared waves.
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.
What is the wavelength range of electromagnetic radiation used in radio broadcast?
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?
Name two electromagnetic waves of wavelength smaller than that of violet light.
