Electromagnetic Waves

If the magnetic field in a plane progressive wave is represented by the equation $B_y=2 \times 10^{-7} \sin \left(0.5 \times 10^3 x+1.5 \pi \times 10^{11} t\right) \mathrm{T}$, then the frequency of the wave is

(In the equation time $t$ is in second)