English

Answer briefly. Give two uses of ultraviolet rays.

Advertisements
Advertisements

Question

Answer briefly.

Give two uses of ultraviolet rays.

Short/Brief Note
Advertisements

Solution

Uses:

  1. Ultraviolet rays destroy germs and bacteria and hence they are used for sterilizing surgical instruments and for purification of water.
  2. Used in burglar alarms and security systems.
  3. Used to distinguish real and fake gems.
shaalaa.com
  Is there an error in this question or solution?
Chapter 13: Electromagnetic Waves and Communication System - Exercises [Page 241]

APPEARS IN

Balbharati Physics [English] Standard 11 Maharashtra State Board
Chapter 13 Electromagnetic Waves and Communication System
Exercises | Q 2. (viii) | Page 241

Video TutorialsVIEW ALL [2]

RELATED QUESTIONS

Use the formula λm T= 0.29 cm K to obtain the characteristic temperature ranges for different parts of the electromagnetic spectrum. What do the numbers that you obtain tell you?


State an additional use of the X-rays waves


The wavelengths for the light of red and blue colours are roughly 7.8 × `10^7` m and 4.8 × `10^7` m respectively.
(a) Which colour has the greater speed in vacuum?
(b) Which colour has the greater speed in glass?


A wave has a wavelength of 10-3 nm. Name the wave.


What is the range of the wavelength of the following electromagnetic waves?

(a) Visible. 


Give the range of wavelength of the electromagnetic waves visible to us.


Why is exposure to X-rays injurious to health but not exposure to visible light, when both are electromagnetic waves?


The energy of a photon of a characteristic X-ray from a Coolidge tube comes from


If the current in the circuit for heating the filament is increased, the cutoff wavelength


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?


Find the cutoff wavelength for the continuous X-rays coming from an X-ray tube operating at 30 kV.

(Use Planck constant h = 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)


The wavelength of Kα X-ray of tungsten is 21.3 pm. It takes 11.3 keV to knock out an electron from the L shell of a tungsten atom. What should be the minimum accelerating voltage across an X-ray tube having tungsten target which allows production of Kα X-ray?

(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)


The wavelengths of Kα and Lα X-rays of a material are 21.3 pm and 141 pm respectively. Find the wavelength of Kβ X-ray of the material.

(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)


The energy of a silver atom with a vacancy in K shell is 25.31 keV, in L shell is 3.56 keV and in M shell is 0.530 keV higher than the energy of the atom with no vacancy. Find the frequency of Kα, Kβ and Lα X-rays of silver.

(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)


What is the velocity of electromagnetic wave?

Name the scientist who discovered Ultraviolet rays


Name the radiation of the electromagnetic spectrum which is used for the following:

Radar and Give the frequency range.


Name two sources of ultraviolet radiation.


Answer briefly.

Why light waves travel in a vacuum whereas sound waves cannot?


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:


Microwaves are electromagnetic waves with frequency in the range of.


What is time period of the light for which the eye is most sensitive?


If λv, λx and λm Am represents the wavelength of visible light, x-ray and microwaves respectively, then ______.


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.


Identify the electromagnetic radiation and write its wavelength range, which is used to kill germs in water purified. Name the two sources of these radiations.


Identify the part of the electromagnetic spectrum which:

  1. produces the heating effect.
  2. is absorbed by the ozone layer in the atmosphere.
  3. is used for studying crystal structure.

Write any one method of the production of each of the above radiations.


What is the speed of radio waves in vacuum?


What is the wavelength range of electromagnetic radiation used in radio broadcast?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×