Apparent change in the wave frequency (or in the period of periodic events) due to motion of wave source and/or observer is known as Doppler effect. In the 17th century (well before Doppler effect was ...
Light wave falling on a glass surface suffers reflection because of impedance mismatch. If Z_g = 250 Ohms (typical), the fraction of power reflection is
^2 = ^2 = 0.04 = 4%,
where Z_0 = sqrt(m ...
In a nondispersive wave medium, waves can propagate without deformation Electromagnetic waves in unbounded free space are nondispersive as well as nondissipative and thus can propagate over astronomic ...
Radiation profile (angular dependence of the Poynting flux = directivity) can be varied by a suitable choice of the number of antennas in an array and the phase angle between neighbouring radiation fi ...
The basic mechanism of electromagnetic radiation is discussed in Note 10. For a charge to radiate electromagentic waves in free space, it must be either accelerated or decelerated. Charges undergoing ...
The differential equation to describe oscillation of a pendulum of length l is
This is a nonlinear equation. For small oscillation amplitude,
it can be linearized as
The oscillation freq ...
Waves are in general dispersive and the original wave form becomes dispersed as waves propagate over a large distance. However, in some waves, dispersion can be compensated by nonlinearity and they ca ...
The impedance for electromagnetic waves is defined as the ratio between the voltage and current waves,
where
are inductance and capacitance per unit length in medium. For example,the i ...
In the lowest order, the velocity of transverse waves in a chain freely hanging maybe
given by
where x is the distance from the lower, free end of the chain. The wave velocity is stronglydep ...
It is difficult for electromagnetic waves to penetrate into a conductor because of severe impedance matching. The impedance of a conductor is given by
where sigma (Siemens/m) is the conductivi ...
