Advertisements
Advertisements
प्रश्न
Answer briefly.
Can we produce a pure electric or magnetic wave in space? Why?
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
Given below are some famous numbers associated with electromagnetic radiations in different contexts in physics. State the part of the electromagnetic spectrum to which each belongs.
(a) 21 cm (wavelength emitted by atomic hydrogen in interstellar space).
(b) 1057 MHz (frequency of radiation arising from two close energy levels in hydrogen; known as Lamb shift).
(c) 2.7 K [temperature associated with the isotropic radiation filling all space-thought to be a relic of the ‘big-bang’ origin of the universe].
(d) 5890 Å - 5896 Å [double lines of sodium]
(e) 14.4 keV [energy of a particular transition in 57Fe nucleus associated with a famous high resolution spectroscopic method (Mössbauer spectroscopy)].
Name the phenomenon which shows the quantum nature of electromagnetic radiation.
Name the high energetic invisible electromagnetic waves which help in the study of the structure of crystals
A wave has a wavelength of 10-3 nm. Name the wave.
State the approximate range of wavelength associated with visible light.
Name the waves produced by the changes in the nucleus of an atom.
Consider a photon of a continuous X-ray coming from a Coolidge tube. Its energy comes from
If the current in the circuit for heating the filament is increased, the cutoff wavelength
The X-ray beam emerging from an X-ray tube
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
Iron emits Kα X-ray of energy 6.4 keV. Calculate the times taken by an iron Kα photon to cross through a distance of 3 km.
(Use Planck constant h = 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
What potential difference should be applied across an X-ray tube to get X-ray of wavelength not less than 0.10 nm? What is the maximum energy of a photon of this X-ray in joule?
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
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 |
If the operating potential in an X-ray tube is increased by 1%, by what percentage does the cutoff wavelength decrease?
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Name the scientist who discovered Ultraviolet rays
Name two sources of infrared radiation.
State two uses of infrared radiations.
Light of wavelength `3500A` is incident on two metals A and B whose work functions are 3.2 eV and 1.9 eV respectively. Which metal will emit photoelectrons?
The fundamental frequency of an open organ pipe is 300 Hz. The first overtone of this pipe has same frequency as first overtone of a closed organ pipe. If speed of sound is 330 m/s, then the length of closed organ pipe is:
Microwaves are electromagnetic waves with frequency in the range of.
The ozone layer absorbs
Following QN ∴ 14, the radiation force on the roof will be
The frequency of e. m waves which is best suited .to observed of radius 3 × 10–4 his of the order of
One requires 11eV of energy to dissociate a carbon monoxide molecule into carbon and oxygen atoms. The minimum frequency of the appropriate electromagnetic radiation to achieve the dissociation lies in ______.
Write two uses of the following radiation.
Gamma rays
Give any two uses of infrared waves.
Name one radiation having the wavelength longer than the wavelength of these radiations.
What happens when an electron collides with a positron?
