\(\therefore \lambda\) in medium \(=\frac{0.1}{\mu}\)
Where refractive index
\(\mu=\sqrt{\mu_{z} \varepsilon_{z}}\)
Assuming non-magnetic material \(\mu_{ r }=1\)
\(\therefore \quad \mu=\sqrt{2.25}=1.5\)
\(\lambda_{ m }=\frac{0.1}{1.5}=\frac{1}{15} m =6.67 \,cm\)
\(=667 \times 10^{-2}\, cm\)
[આપેલ : પ્રકાશની ઝડપ $c =3 \times 10^{8} \,ms ^{-1}$, શુન્યાવકાશની પરમીએબિલીટી $\mu_{0}=4 \pi \times 10^{-7} \,NA ^{-2}$]
[$\left.\varepsilon_{0}=8.85 \times 10^{-12} \,{F} / {m}\right]$