1. For a plane electromagnetic wave in a medium,

$\frac{E}{H} = \eta$

where $\eta$ is the intrinsic impedance of the medium.

2. Intrinsic impedance of a medium is

$\eta = \sqrt{\frac{\mu}{\varepsilon}}$

Using relative permeability and relative permittivity,

$\eta = \sqrt{\frac{\mu_r \mu_0}{\varepsilon_r \varepsilon_0}} = \sqrt{\frac{\mu_r}{\varepsilon_r}}\sqrt{\frac{\mu_0}{\varepsilon_0}}$

But

$\sqrt{\frac{\mu_0}{\varepsilon_0}} = \eta_0 = \mu_0 c = 120\pi\ \Omega$

So,

$\eta = 120\pi \sqrt{\frac{\mu_r}{\varepsilon_r}}$

3. Given:

$\mu_r = 1.61, \qquad \varepsilon_r = 6.44, \qquad H = 4.5\times 10^{-2}\ \text{A m}^{-1}$

Now,

$\frac{\mu_r}{\varepsilon_r} = \frac{1.61}{6.44} = 0.25$

Hence,

$\sqrt{\frac{\mu_r}{\varepsilon_r}} = \sqrt{0.25} = 0.5$

Therefore,

$\eta = 120\pi \times 0.5 = 60\pi\ \Omega$

4. Now calculate electric field intensity:

$E = \eta H = 60\pi \times 4.5\times 10^{-2}$

$E = 2.7\pi$

Using $\pi \approx 3.14$,

$E \approx 2.7 \times 3.14 = 8.48\ \text{V m}^{-1}$

5. Comparing with options:

• A: $16.96\ \text{V m}^{-1}$
• B: $2.25\times 10^{-2}\ \text{V m}^{-1}$
• C: $8.48\ \text{V m}^{-1}$
• D: $6.75\times 10^6\ \text{V m}^{-1}$

So the correct option is C.