The electric field associated with an em wave in vacuum is given by
E = $$\widehat i$$ 40 cos (kz $$-$$ 6 $$ \times $$ 10⁸ t) where E, z and t are in volt/m, meter and seconds respectively. The value of wave vector k is

The electric and the magnetic field, associated with an e.m. wave, propagating along the +z-axis, can be represented by

The decreasing order of wavelength of infrared, microwave, ultraviolet and gamma rays is

The electric field of an electromagnetic wave in free space is given by $$\overrightarrow E = 10\cos ({10^7}t + kx)\widehat j\,\,V/m,$$ where t and x are in seconds and metres respectively. It can be inferred that
(1)  the wavelength $$\lambda $$ is 188.4 m.
(2)  the wave number k is 0.33 rad/m.
(3)  the wave amplitude is 10 V/m.
(4)  the wave is propagating along +x direction.

Which one of the following pairs of statements is correct ?