AP EAPCET 24-Aug-2021 Shift 1 Paper

Given that, equation of electric field of an electromagnetic wave in vacuum, E=(3.1NC−1)
cos[(1.8‌rad‌‌‌m−1)y+(54×106‌rad‌‌‌s−1)1]‌

^

i

...(i)
We know that, general equation
E=E0‌cos[ky+wt]‌

^

i

...(ii)
Comparing Eqs. (i) and (ii), we getPropagation constant, k=1.8‌rad∕m
i.e.,

2π

λ

=1.8
⇒λ=

2π

1.8

=3.49m
Hence, wavelength of electromagnetic wave is 3.49m.