The given equation represents a plane electromagnetic wave of the form:
$$ E = E_0 \sin (kx - \omega t) $$
From the given equation:
$$ k = 3 \times 10^6\ \text{rad/m} $$
$$ \omega = 4.5 \times 10^{14}\ \text{rad/s} $$
The speed of the electromagnetic wave in the medium is:
$$ v = \frac{\omega}{k} $$
$$ v = \frac{4.5 \times 10^{14}}{3 \times 10^6} = 1.5 \times 10^8\ \text{m/s} $$
For a nonmagnetic medium:
$$ v = \frac{c}{\sqrt{K}} $$
where $K$ is the dielectric constant of the medium.
$$ \sqrt{K} = \frac{c}{v} = \frac{3 \times 10^8}{1.5 \times 10^8} = 2 $$
$$ K = 4 $$
Hence, the dielectric constant of the medium is:
4
Updated for JEE Main 2026: This PYQ is important for JEE Mains, JEE Advanced and other competitive exams. Practice more questions from this chapter.