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प्रश्न
Choose the correct option.
How does the frequency of a beam of ultraviolet light change when it travels from air into glass?
विकल्प
depends on the values of μ and ε
increases
decreases
remains same
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उत्तर
remains same
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संबंधित प्रश्न
To which part of electromagnetic spectrum does a wave of frequency 3 × 1013 Hz belong?
To which part of the electromagnetic spectrum does a wave of frequency 5 × 1019 Hz belong?
To which part of the electromagnetic spectrum does a wave of frequency 5 × 1011 Hz belong?
What physical quantity is the same for X-rays of wavelength 10−10 m, red light of wavelength 6800 Å and radiowaves of wavelength 500 m?
Why are infra-red waves often called heat waves? Explain.
Name the subjective property of light related to its wavelength.
Arrange the following radiations in the order of their increasing wavelength:
X-rays, infrared rays, ratio waves, gamma ray and microwaves.
Give one use of microwaves.
Name of physical quantity which remains same for microwaves of wavelength 1 mm and UV radiations of 1600 Å in vacuum.
Consider a photon of a continuous X-ray coming from a Coolidge tube. Its energy comes 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-rays coming from a Coolidge tube are able to pass through a 0.1 mm thick aluminium foil. If the potential difference between the target and the filament is increased, the fraction of the X-rays passing through the same foil will be
For harder X-rays,
(a) the wavelength is higher
(b) the intensity is higher
(c) the frequency is higher
(d) the photon energy is higher.
Cutoff wavelength of X-rays coming from a Coolidge tube depends on the
(a) target material
(b) accelerating voltage
(c) separation between the target and the filament
(d) temperature of the filament.
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 |
Calculate the shortest wavelength of electromagnetic radiation present in Balmer series of hydrogen spectrum.
Give one use of electromagnetic radiation in Ultraviolet radiation.
Name the radiations used for the detection of fracture in bones.
State two uses of infrared radiations.
Solve the numerical problem.
Calculate the wavelength in nm of an X-ray wave of frequency 2.0 × 1018 Hz.
Solve the numerical problem.
The speed of light is 3 × 108 m/s. Calculate the frequency of red light of a wavelength of 6.5 × 10−7 m.
If the Earth did not have atmosphere, would its average surface temperature be higher or lower than what it is now? Explain.
An e.m. wave exerts pressure on the surface on which it is incident. Justify.
The ratio of contributions made by the electric field and magnetic field components to the intensity of an EM wave is ______.
What happens to the intensity of light from a bulb if the distance from the bulb is doubled? As a laser beam travels across the length of a room, its intensity essentially remains constant. What geometrical characteristic of LASER beam is responsible for the constant intensity which is missing in the case of light from the bulb?
Electromagnetic waves with wavelength
- λ1 is suitable for radar systems used in aircraft navigation.
- λ2 is used to kill germs in water purifiers.
- λ3 is used to improve visibility in runways during fog and mist conditions.
Identify and name the part of the electromagnetic spectrum to which these radiations belong. Also arrange these wavelengths in ascending order of their magnitude.
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.
Given below in the left column are different modes of communication using the kinds of waves given in the right column.
| A. | Optical Fibre Communication |
P. | Ultrasound |
| B. | Radar | Q. | Infrared Light |
| C. | Sonar | R. | Microwaves |
| D. | Mobile Phones | S. | Radio Waves |
From the options given below, find the most appropriate match between entries in the left and the right column.
