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

Answer briefly. What is a carrier wave?

Advertisements
Advertisements

प्रश्न

Answer briefly.

What is a carrier wave?

एका वाक्यात उत्तर
Advertisements

उत्तर

The high-frequency waves on which the signals to be transmitted are superimposed are called carrier waves.

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. (xiii) | पृष्ठ २४१

व्हिडिओ ट्यूटोरियलVIEW ALL [2]

संबंधित प्रश्‍न

To which part of the electromagnetic spectrum does a wave of frequency 5 × 1019 Hz belong?


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?


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


Name the region beyond  the red end  of the spectrum.


Give one use of microwaves.


Give one use of ultraviolet radiation.


An electromagnetic wave has a frequency of 500 MHz and a wavelength of 60 cm Calculate the velocity of the wave.


An electromagnetic wave has a frequency of 500 MHz and a wavelength of 60 cm.name the medium through which it is travelling


Characteristic X-rays may be used to identify the element from which they are being emitted. Can continuous X-rays be used for this purpose?


Is it possible that in a Coolidge tube characteristic Lα X-rays are emitted but not Kα X-rays?


Can a hydrogen atom emit characteristic X-rays?


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,


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.)


Name the scientist who discovered Infra-red waves


State the name and the range of wavelength of the invisible electromagnetic waves beyond the red end of the visible spectrum.


Name three radiations and their wavelength range which are invisible and beyond the violet end of the visible spectrum.


Name two sources of infrared radiation.


Give one use of electromagnetic radiation in Microwaves.


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


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


SONAR emits which of the following waves?


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?


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?


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.


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.


Below is an incomplete table showing the arrangement of electromagnetic spectrum in the increasing order of their wavelength. Complete the table:

Gamma ray X - ray UV rays Visible rays Infrared A Radio waves
  1. Identify the radiation A.
  2. Name the radiation used to detect fracture in bones.
  3. Name one property common to both A and Radio waves.

What is the speed of radio waves in vacuum?


In an atom X, electrons absorb the energy from an external source. This energy “excites” the electrons from a lower-energy level to a higher-energy level around the nucleus of the atom. When electrons return to the ground state, they emit photons.

The figure below is the energy level diagram of atom X with three energy levels, E1 = 0.00eV, E2 = 1.78eV and E3 = 2.95eV. The ground state is considered 0 eV for reference. The transition of electrons takes place between levels E1 and E2.

  1. What wavelength of radiation is needed to excite the atom to energy level E2 from E1?
  2. Suppose the external source has a power of 100 W. What would be the rate of photon emission?

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×