Advertisements
Advertisements
प्रश्न
Answer briefly.
What is a carrier wave?
उत्तर
The high-frequency waves on which the signals to be transmitted are superimposed are called carrier waves.
APPEARS IN
संबंधित प्रश्न
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?
Name the region beyond the violet end of the spectrum called.
State the approximate range of wavelength associated with the ultraviolet rays.
Two waves A and B have wavelength 0.01 Å and 9000 Å respectively.
- Name the two waves.
- Compare the speeds of these waves when they travel in vacuum.
Name two sources, each of infrared radiations and ultraviolet radiations.
If the current in the circuit for heating the filament is increased, the cutoff wavelength
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
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.)
Name the scientist who discovered Microwaves
Name the scientist who discovered Infra-red waves
Name the radiation which can be detected by thermopile.
Name the part of the electromagnetic spectrum which is:
Suitable for radar systems used in aircraft navigation.
Name the part of the electromagnetic spectrum which is:
Produced by bombarding a metal target with high electrons.
Name the radiation of the electromagnetic spectrum which is used for the following:
Radar and Give the frequency range.
Choose the correct option.
The EM wave emitted by the Sun and responsible for heating the Earth’s atmosphere due to greenhouse effect is
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.
Calculate the wavelength of a microwave of a frequency of 8.0 GHz.
Light of wavelength `3500A` is incident on two metals A and B whose work functions are 3.2 eV and 1.9 eV respectively. Which metal will emit photoelectrons?
The ozone layer absorbs
The area to be covered for T.V telecast is doubled then the height of transmitting antenna (T.V tower) will have to be:-
All components of the electromagnetic spectrum in a vacuum have the same ______
The ratio of contributions made by the electric field and magnetic field components to the intensity of an EM wave is ______.
Arrange the following electromagnetic radiation in the ascending order of their frequencies:
X-rays, microwaves, gamma rays, radio waves
Write two uses of the following radiation.
X-rays
Which is the correct ascending order of wavelengths?
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 |
- Identify the radiation A.
- Name the radiation used to detect fracture in bones.
- Name one property common to both A and Radio waves.
What is the wavelength range of electromagnetic radiation used in radio broadcast?
Name two electromagnetic waves of wavelength smaller than that of violet light.
