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PSTCL JE EE 2016 Official Paper (Held on 8 Oct 2016)

Option 3 : \(\sqrt {\dfrac{\mu}{ \epsilon}}\)

**Concept:**

- Electric field \(\left( {\vec E} \right)\) & magnetic field \(\left( {\vec H} \right)\) are both orthogonal/transverse to each other as well as for the direction of propagation, called transverse electromagnetic wave (TEM).
- E & H combination called uniform plane wave because E & H has some magnitude through any transverse plane.

Intrinsic Impedance \(\left( \eta \right) = \frac{E}{H}\)

And also \(\eta = \sqrt {\frac{{j\omega \mu }}{{\sigma + j\omega \varepsilon }}} \)

But for free space

\( \Rightarrow \eta = \frac{E}{H} = \sqrt {\frac{\mu }{\varepsilon }} \)

Pointing vector is a vector whose direction is the direction of wave propagation pointing vector \( = \vec E \times \vec H\) (Hence it is a direction of wave propagation)

Where,

E = Electric filed

B = magnetic field

H = Magnetic field

μ0 = Permeability of free space = 4π x 10-7 H / m

ϵ0 = Permittivity of free space = 8.85 x 10-12 F/m