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प्रश्न
Answer briefly.
Does an ordinary electric lamp emit EM waves?
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उत्तर
Yes, an ordinary electric lamp emits EM waves.
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संबंधित प्रश्न
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?
What is the range of the wavelength of the following electromagnetic waves?
(A) Radio waves.
Name the rays or waves of highest frequency .
Name the waves used for taking photographs in dark.
Name the waves produced by the changes in the nucleus of an atom.
Name of physical quantity which remains same for microwaves of wavelength 1 mm and UV radiations of 1600 Å in vacuum.
How are X-rays produced?
Which part of electromagnetic spectrum is used in radar systems?
Why is exposure to X-rays injurious to health but not exposure to visible light, when both are electromagnetic waves?
Consider a photon of continuous X-ray and a photon of characteristic X-ray of the same wavelength. Which of the following is/are different for the two photons?
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.)
The electron beam in a colour TV is accelerated through 32 kV and then strikes the screen. What is the wavelength of the most energetic X-ray photon?
(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.)
Name the scientist who discovered radio waves
Name the scientist who discovered Ultraviolet rays
State the name and the range of wavelength of the invisible electromagnetic waves beyond the red end of the visible spectrum.
Name the radiation of the electromagnetic spectrum which is used for the following:
To photograph internal parts of the human body and Give the frequency range
Gamma rays and radio waves travel with the same velocity in free space. Distinguish between them in terms of their origin and the main application.
Name any two electromagnetic waves which have a frequency higher than that of violet light. State one use of each.
What are the ultraviolet rays?
Answer briefly.
Why high-frequency carrier waves are used for the transmission of audio signals?
An e.m. wave exerts pressure on the surface on which it is incident. Justify.
A car is moving towards a high cliff. The car driver sounds a horn of frequency f. The reflected sound heard by the driver has a frequency 2f. If v be the velocity of sound, then the velocity of the car, in the same velocity units, will be:
What is time period of the light for which the eye is most sensitive?
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.
X-rays
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.
