How are electromagnetic waves produced? What is the source of energy of these waves? Write mathematical expressions for electric and magnetic fields of an electromagnetic wave propagating along the z-axis. Write any two important properties of electromagnetic waves.
CBSE OUTSIDE DELHI - SET 2 NORTH 2016
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$\varepsilon.\text{M}.$ waves are produced by accelerated/oscillating charges.
Source of energy is the source that accelerates the charges Expression for the electric and magnetic fields (for an e.m. wave propagating along the z – axis) can be
$\text{E}_{x} = \text{E}_{0}\sin(kz - \omega\text{t})$
$\text{B}_{y} - \text{B}_{0}\sin(kz - \omega\text{t})$
Properties:
Source of energy is the source that accelerates the charges Expression for the electric and magnetic fields (for an e.m. wave propagating along the z – axis) can be
$\text{E}_{x} = \text{E}_{0}\sin(kz - \omega\text{t})$
$\text{B}_{y} - \text{B}_{0}\sin(kz - \omega\text{t})$
Properties:
- Transverse nature.
- Have a definite speed (for all frequencies) in vacuum.
- Can be polarised.
- Can show the phenomenon of interference and diffraction.
- Can transport energy from one point to another.
- Have oscillating electric and magnetic fields along mutually perpendicular directions.
- Have a momentum associated with them.
- Their speed, in a medium, depends upon the values of $\mu$ and $\varepsilon$ for that medium.
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