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प्रश्न
Answer briefly.
Name the most harmful radiation entering the Earth's atmosphere from outer space.
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उत्तर
Name the most harmful radiation entering the Earth's atmosphere from outer space – Ultraviolet radiation
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संबंधित प्रश्न
Identify the part of the electromagnetic spectrum which is:
produced by bombarding a metal target by high speed electrons.
Name the parts of the electromagnetic spectrum which is
used to treat muscular strain.
Write in brief, how these waves can be produced.
If the earth did not have atmosphere, would its average surface temperature be higher or lower than what it is now? Explain.
What is the range of the wavelength of the following electromagnetic waves?
(a) Visible.
What is the range of the wavelength of the following electromagnetic waves?
(A) Radio waves.
An electromagnetic wave has a frequency of 500 MHz and a wavelength of 60 cm.name the medium through which it is travelling
When a Coolidge tube is operated for some time it becomes hot. Where does the heat come from?
The figure shows the intensity-wavelength relations of X-rays coming from two different Coolidge tubes. The solid curve represents the relation for the tube A in which the potential difference between the target and the filament is VA and the atomic number of the target material is ZA. These quantities are VB and ZB for the other tube. Then,
50% of the X-ray coming from a Coolidge tube is able to pass through a 0.1 mm thick aluminium foil. The potential difference between the target and the filament is increased. The thickness of the aluminium foil that will allow 50% of the X-ray to pass through will be
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 short-wavelength limit shifts by 26 pm when the operating voltage in an X-ray tube is increased to 1.5 times the original value. What was the original value of the operating voltage?
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Continuous X-rays are made to strike a tissue paper soaked with polluted water. The incoming X-rays excite the atoms of the sample by knocking out the electrons from the inner shells. Characteristic X-rays are analysed and the intensity is plotted against the wavelength. Assuming that only Kα intensities are detected, list the elements present in the sample from the plot. Use Moseley's equation v − (25 × 1014Hz)(Z − 1)2.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
| Gamma rays | D | C | Visible light | B | A |
The above table shows different parts of the electromagnetic spectrum.
(a) Identify the parts of the spectrum marked as A, B, C and D.
(b) Which of the radiations A or B has the higher frequency?
(c) State two properties which are common to all parts of the electromagnetic spectrum.
(d) Name one source of each of the radiation of electromagnetic spectrum.
(e) Name one detector for each of the radiation.
(f) Name one use of each of the radiation.
Identify the part of the electromagnetic spectrum used in (i) radar and (ii) eye surgery. Write their frequency range.
State three properties of ultra-violet radiation similar to visible light.
Give one use of electromagnetic radiation in Ultraviolet radiation.
Answer briefly.
Give two uses of ultraviolet rays.
A bat moving at 10 ms−1 towards a wall sends a sound signal of 8000 Hz towards it. On reflection, it hears a sound of frequency f The value of f in Hz is close to (speed of sound = 320 ms−1)
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:
The frequency of x-rays, y-rays and ultraviolet rays are respectively a, b and c. Then:-
The area to be covered for T.V telecast is doubled then the height of transmitting antenna (T.V tower) will have to be:-
SONAR emits which of the following waves?
The electric field intensity produced by the radiations coming from 100 W bulb at a 3 m distance is E. The electric field intensity produced by the radiations coming from 50 W bulb at the same distance is ______.
The half-value thickness of an absorber is defined as the thickness that will reduce exponentially the intensity of a beam of particles by a factor of 2. The half-value thickness in (µm) for lead assuming X-ray beam of wavelength 20 pm, µ = 50 cm-1 for X-rays in lead at wavelength λ = 20 pm, is ______ µm.
Which one of the following electromagnetic radiation has the least wavelength?
Choose the correct option related to wavelengths (λ) of different parts of the electromagnetic spectrum.
What happens when an electron collides with a positron?
Name the electromagnetic radiation that has been used in obtaining the image below.
