JEE Main · 2022 · 27 Jun 2022 · Shift 2 · EM Waves

Statement I is correct: Maxwell's equations show that a time-varying electric field produces a magnetic field and vice versa, which is the basis of electromagnetic wave propagation.

Statement II is incorrect: The speed $v=\frac{1}{\sqrt{{\mu }_0{\epsilon }_0}}$ is the speed of EM waves in vacuum (free space), which equals $c=3\times 10^8$ m/s. In a material medium with relative permittivity ${\epsilon }_r$ and relative permeability ${\mu }_r$, the speed is:

$v=\frac{1}{\sqrt{\mu \epsilon }}=\frac{1}{\sqrt{{\mu }_0{\mu }_r{\epsilon }_0{\epsilon }_r}}=\frac{c}{\sqrt{{\mu }_r{\epsilon }_r}}$

Therefore, Statement I is correct but Statement II is false.