मराठी
महाराष्ट्र राज्य शिक्षण मंडळएचएससी विज्ञान (सामान्य) इयत्ता ११ वी

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.

Advertisements
Advertisements

प्रश्न

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.

बेरीज
Advertisements

उत्तर

Given: c = 3 × 108 m/s, λ = 6.5 × 10–7 m

To find: Frequency (ν)

Formula: c = νλ

Calculation: From formula,

ν = `"c"/λ=(3xx10^8)/(6.5xx10^-7)` = 4.6 × 1014 Hz

The frequency of red light is 4.6 × 1014 Hz.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 13: Electromagnetic Waves and Communication System - Exercises [पृष्ठ २४१]

APPEARS IN

बालभारती Physics [English] Standard 11 Maharashtra State Board
पाठ 13 Electromagnetic Waves and Communication System
Exercises | Q 3. (iii) | पृष्ठ २४१

व्हिडिओ ट्यूटोरियलVIEW ALL [2]

संबंधित प्रश्‍न

Identify the part of the electromagnetic spectrum which is suitable for radar system used in aircraft navigation.


What do you understand by the statement, "Electromagnetic waves transport momentum"?


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

(a)X-rays,


Name the waves of wavelength nearly 0.1 nm.


How are X-rays produced?


When a Coolidge tube is operated for some time it becomes hot. Where does the heat come from?


Can X-rays be polarised?


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.


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 electric current in an X-ray tube (from the target to the filament) operating at 40 kV is 10 mA. Assume that on an average, 1% of the total kinetic energy of the electron hitting hte target are converted into X-rays.
(a) What is the total power emitted as X-rays and (b) how much heat is produced in the target every second?


Heat at the rate of 200 W is produced in an X-ray tube operating at 20 kV. Find the current in the circuit. Assume that only a small fraction of the kinetic energy of electrons is converted into X-rays.


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.)


What is the cause of dispersion?

Name the scientist who discovered radio waves


Identify the part of the electromagnetic spectrum used in
(i) radar and
(ii) eye surgery. Write their 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.


How will you investigate the existence of the radiation beyond the red and violet extremes of the spectrum?


Name two sources of infrared radiation.


State three properties of ultra-violet radiation similar to visible light.


Calculate the wavelength of a microwave of a frequency of 8.0 GHz.


An e.m. wave exerts pressure on the surface on which it is incident. Justify.


Microwaves are electromagnetic waves with frequency in the range of.


The ratio of contributions made by the electric field and magnetic field components to the intensity of an EM wave is ______.


The magnetic field of a beam emerging from a filter facing a floodlight is given by B0 = 12 × 10–8 sin (1.20 × 107z – 3.60 × 1015t) T. What is the average intensity of the beam?


Electromagnetic waves with wavelength

  1. λ1 is suitable for radar systems used in aircraft navigation.
  2. λ2 is used to kill germs in water purifiers.
  3. 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.


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.


Assertion (A): Ultraviolet radiations is scattered more as compared to the microwave radiations.

Reason (R): Wavelength of ultraviolet radiation is more than the wavelength of microwave radiation.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×