Question

The velocity of electromagnetic waves in a dielectric medium $({\epsilon }_r=4)$ is

• A. $7.5\times {10}^7$ meter /second
• B. $6\times {10}^8$ meter /second
• C. $1.5\times {10}^8$ meter /second
• D. $3\times {10}^8$ meter /second

Answer 1

The correct option is A $7.5\times {10}^7$ meter /second

Given: ${\epsilon }_r=4$

The velocity of electromagnetic wave in a dielectric medium is given by,

$v=\frac{c}{{\epsilon }_r}=\frac{3\times {10}^8}{4}=7.5\times {10}^7\text{m/s}$

Hence, option $\left(D\right)$ is correct.