If the magnetic field of a plane electromagnetic wave is given by  B=1×10−6sin[0.4×102x+0.3×1010t]T. Then the speed of the wave is

Given equation is  B=1×10−6sin[0.4×102x+0.3×1010t]TComparing the given equation with the equation of  B=B0sin[Kx+ωt]Then  K=0.4×102m−1  &ω=0.3×1010rad/sSpeed of the wave is  V=ωK=0.30.4×1010102=34×108⇒V=0.75×108m/s