Speed of electromagnetic wave in a medium of `in_(r )=1.3` and `mu_(r )=2.14` is ……. .

Options

A. `3.6xx10^(8)m//s`
B. `1.8xx10^(8)m//s`
C. `1.8xx10^(6)m//s`
D. `13.6xx10^(6)m//s`

Answer

B

Explanation

`n=(c )/(v)`
`therefore v=(c )/(n)` but `n = sqrt(mu_(r )in_(r ))`
`therefore v=(c )/(sqrt(my_(r )in_(r )))`
`= (3xx10^(8))/(sqrt(2.14xx1.3))`
`= (3xx10^(8))/(sqrt(2.782))=(3xx10^(8))/(1.67)`
`therefore v=1.796xx10^(8)`
`therefore v ~~ 1.8 xx 10^(8)m//s`