Solve Example on Poynting Theorem
Q1. The Poynting vector of an electromagnetic wave in .What is the wavelength?
Solve:
we know that
direction of wave propagation (kz-wt): the wave is propagating in the x direction.
where
where w=angular frequency and k=wave number
=
so ,Given
k=9
wave length = =2*pi/9= 0.698 meter
Q2. A radio transmitter emits an electromagnetic wave with an electric field magnitude of 4v/m and a magnetic of 2 UoT. Calcualated the manitude of the poynting vector at a point where the angle E and B is 30 degree.
Solve:
Given :
E=4, B=2,
=30 degree
use the formula
Q3. A LBM with an electric field magnitude of 10V/m and a magnetic field magnitude of 4 UoT is used an optical experiment .calculate the poynting vector magnitude.
solve:
Given,
E=10,B=4
=90
So, P=E x B
P=
P=
Poynting Theorem
The Poynting Theorem which was named After the British Physicist John Henry Poynting is a concept in electromagnetism that describes the energy inflow in an electromagnetic field. It Establishes a connection between the electromagnetic fields and the rate of energy transfer in a given region of space. Mathematically, it’s expressed as the cross-product of the electric field( E) and the magnetic field( H). It represents the power per unit area, or intensity, of the electromagnetic field. In this article, we will be Going Through The Poynting Theorem and its Mathematical Representations and Derive Some Equations.
Table of Content
- What is the Poynting Theorem?
- Mathematical Representation
- Proof of Poynting Theorem
- Derivation of Average power
- Derivation of Average Power Density
- Advantages and Disadvantages
- Application
- Solve Example
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