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

Answer briefly. Why high-frequency carrier waves are used for the transmission of audio signals? - Physics

Advertisements
Advertisements

प्रश्न

Answer briefly.

Why high-frequency carrier waves are used for the transmission of audio signals?

टीपा लिहा
Advertisements

उत्तर

An audio signal has a low frequency (< 20 kHz) and low-frequency signals cannot be transmitted over large distances. Because of this, high-frequency carrier waves are used for transmission.

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 2. (xiv) | पृष्ठ २४१

व्हिडिओ ट्यूटोरियलVIEW ALL [2]

संबंधित प्रश्‍न

The terminology of different parts of the electromagnetic spectrum is given in the text. Use the formula E = hv (for energy of a quantum of radiation: photon) and obtain the photon energy in units of eV for different parts of the electromagnetic spectrum. In what way are the different scales of photon energies that you obtain related to the sources of electromagnetic radiation?


Give a reason for the following:

Long-distance radio broadcasts use short-wave bands. Why?


If the earth did not have an atmosphere, would its average surface temperature be higher or lower than what it is now?


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


(a) Give a list of at least five radiations, in order of their increasing frequencies, which make up the complete electromagnetic spectrum.

(b) Which of the radiation mentioned by you in part (a) has the highest penetrating power.


State the approximate range of wavelength associated with the ultraviolet rays.


The wavelength of X-rays is 0.01 Å. Calculate its frequency. State the assumption made, if any.


Moseley's Law for characteristic X-ray is √v = a(Z − b). Here,


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.


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.)


Find the maximum potential difference which may be applied across an X-ray tube with tungsten target without emitting any characteristic K or L X-ray. The energy levels of the tungsten atom with an electron knocked out are as follows.

Cell containing vacancy K L M
Energy in keV 69.5 11.3 2.3

The Kα and Kβ X-rays of molybdenum have wavelengths 0.71 A and 0.63 A respectively. Find the wavelength of Lα X-ray of molybdenum.


When 40 kV is applied across an X-ray tube, X-ray is obtained with a maximum frequency of 9.7 × 1018 Hz. Calculate the value of Planck constant from these data.

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


The stopping potential in a photoelectric experiment is linearly related to the inverse of the wavelength (1/λ) of the light falling on the cathode. The potential difference applied across an X-ray tube is linearly related to the inverse of the cutoff wavelength (1/λ) of the X-ray emitted. Show that the slopes of the lines in the two cases are equal and find its value.

(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


To which regions of the electromagnetic spectrum do the following wavelengths belong: 
(a) 250 nm 
(b) 1500 nm 


Name two sources of ultraviolet 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.


Which of the following is a tool used for separating the different color wavelengths from each other?


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:


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


SONAR emits which of the following waves?


Arrange the following electromagnetic radiation in the ascending order of their frequencies:

X-rays, microwaves, gamma rays, radio waves


Electromagnetic waves of wavelengths λ1, λ2 and λ3 are used in a radar system, in water purifiers and in remote switches of TV, respectively.

  1. Identify the electromagnetic waves.
  2. Write one source for each of them.

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×