Advertisements
Advertisements
प्रश्न
Answer briefly.
Does an ordinary electric lamp emit EM waves?
Advertisements
उत्तर
Yes, an ordinary electric lamp emits EM waves.
APPEARS IN
संबंधित प्रश्न
How are infrared waves produced?
Identify the part of the electromagnetic spectrum which is suitable for radar system used in aircraft navigation.
If the earth did not have atmosphere, would its average surface temperature be higher or lower than what it is now? Explain.
To which part of the electromagnetic spectrum does a wave of frequency 5 × 1011 Hz belong?
If the earth did not have an atmosphere, would its average surface temperature be higher or lower than what it is now?
Name the phenomenon which shows the quantum nature of electromagnetic radiation.
(a) Give a list of at least five radiations, in order of their increasing frequencies, which make up the complete electromagnetic spectrum.
(b) Which of the radiation mentioned by you in part (a) has the highest penetrating power.
What is the range of the wavelength of the following electromagnetic waves?
(a) Micro waves .
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.
Give one use of ultraviolet radiation.
Two waves A and B have wavelength 0.01 Å and 9000 Å respectively.
- Name the two waves.
- Compare the speeds of these waves when they travel in vacuum.
Can Lα X-ray of one material have shorter wavelength than Kα X-ray of another?
The energy of a photon of a characteristic X-ray from a Coolidge tube comes from
The X-ray beam emerging from an X-ray tube
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 |
Heat at the rate of 200 W is produced in an X-ray tube operating at 20 kV. Find the current in the circuit. Assume that only a small fraction of the kinetic energy of electrons is converted into X-rays.
The Kα X-rays of aluminium (Z = 13) and zinc (Z = 30) have wavelengths 887 pm and 146 pm respectively. Use Moseley's law √v = a(Z − b) to find the wavelengths of the Kα X-ray of iron (Z = 26).
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
A free atom of iron emits Kα X-rays of energy 6.4 keV. Calculate the recoil kinetic energy of the atom. Mass of an iron atom = 9.3 × 10−26 kg.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Name the radiations used for the detection of fracture in bones.
What is the wavelength of the wave whose frequency is 1012 Hz? Name the electromagnetic wave.
Answer briefly.
Can we produce a pure electric or magnetic wave in space? Why?
Solve the numerical problem.
Calculate the frequency in MHz of a radio wave of wavelength 250 m. Remember that the speed of all EM waves in a vacuum is 3.0 × 108 m/s.
Microwaves are electromagnetic waves with frequency in the range of.
The area to be covered for T.V telecast is doubled then the height of transmitting antenna (T.V tower) will have to be:-
Ozone layer above the earth's atmosphere will
Electromagnetic waves of wavelengths λ1, λ2 and λ3 are used in a radar system, in water purifiers and in remote switches of TV, respectively.
- Identify the electromagnetic waves.
- Write one source for each of them.
