Q.

A plane EM wave is propagating along x direction. It has a wavelength of 4 mm. If electric field is in y direction with the maximum magnitude of 6O Vm-1, the equation for magnetic field is          [2024]

1 Bz=60sin[π2(x-3×108t)]k^T  
2 Bz=2×10-7sin[π2×103(x-3×108t)]k^T  
3 Bx=60sin[π2(x-3×108t)]i^T  
4 Bz=2×10-7sin[π2(x-3×108t)]k^T  

Ans.

(2)     

             λ=4mm=4×10-3m

             K=2π4×10-3=π2×103·m-1

             ω=v×K=3×108×π2×103=3π2×1011rad/s

             Electric field y direction

             Propagation field x direction

             Mgnetic field z direction

             E^×B^=c^ and B0=E0c=2×10-7T

            Bz=2×10-7sin[π2×103(x-3×108t)]k^T