The electric field associted with an electromagnetic wave in vacuum is given by `vecE=hati 40 cos(kz=6xx10^(8)t)`, when `E`, `z` and `t` are in volt/m metre and second respectively
find the wave vector.

Options

A. `2m^(-1)`
B. `0.5m^(-1)`
C. `6m^(-1)`
D. `3m^(-1)`

Answer

A

Explanation

`vec(E) = hati 40 cos (kz - omegat)`
`omega = 6xx10^(8) rad//sec`
`k = (omega)/(c ) = (6 xx 10^(8))/(3xx10^(8)) = 2m^(-1)`