Question
Write a short note on radio waves.

Answer

→Radio waves are produced by the accelerated motion of charges in conducting wires.
→They are used in radio and television communication systems.
→Frequency range: from 500 kHz to about 1000 MHz.
→Range of frequencies for different bands:
(i) AM (Amplitude Modulated) band: from 530 kHz to 1710 kHz
(ii) SW band: Up to 54 MHz
(iii) TV waves band: 54 MHz to 890 MHz
(iv) FM (Frequency Modulated) radio band: 88 MHz to 108 MHz
(v) UHF (Ultra High Frequency band: 300 MHz to 3000 MHz.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

A current is induced in coil $C_1$ due to the motion of current carrying coil $C_2. (a)$ Write any two ways by which a large deflection can be obtained in the galvanometer $G. (b)$ Suggest an alternative device to demonstrate the induced current in place of a galvanometer.
What is absolute refractive index? On what factors does it depend ?
A driver takes $0.20s$ to apply the brakes after he sees a need for it. This is called the reaction time of the driver. If he is driving a car at a speed of $54\ km/h$ and the brakes cause a deceleration of $6.0m/s^2,$ find the distance travelled by the car after he sees the need to put the brakes on.
The net charge in a current-carrying wire is zero. Then, why does a magnetic field exert a force on it?
An inductor-coil of inductance $17\ mH$ is constructed from r wire of length 100m and cross-sectional area a copper wire of length $100m$ and cross-sectional area $1mm^2$. Calculate the time constant of the circuit if this inductor is joined across an ideal battery. The resistivity of copper $=1.7\times10^{-8}\Omega-\text{m}.$
In order to have a current in a long wire, it should be connected to a battery or some such device. Can we obtain the magnetic due to a straight, long wire by using Ampere's law without mentioning this other part of the circuit?
A 5 m long straight horizontal conducting wire situated in the east to west direction is falling with a speed of $2 m / s$ perpendicular to the horizontal component of the earth magnetic field of $0.3 \times 10^{-4} T$. Find the instantaneous value of the emf induced between the ends of the wire.
A parallel beam of monochromatic light falls normally on a single narrow slit. How does the angular width of the principal maximum in the resulting diffraction pattern depend on the width of the slit?
The energy of electron in hydrogen atom in its ground state is - 13.6 eV. Calculate kinetic energy and potential energy of electron in this state.
  1. The peak voltage of an ac supply is $300V$. What is the rms voltage?
  2. The rms value of current in an ac circuit is $10A$. What is the peak current?