Question

The electric field of a plane polarized electromagnetic wave in free space at time t= 0 is given by an expression e x,y 10 j cos [(6x + 8z)] the magnetic field b (x, z, t) is given by : (c is the velocity of light)

Answer 1

Answer:

Explanation:

For a A plane EM wave traveling in the x-direction is of the form

E (x,y) = 10j cos[(6x+8z)]

B( x,y,z) = B0 cos[(6x+8z)] - eq 1

where B0 = E0/C

Now since E is in the direction of j

Similarly the direction of wave is along αi+βk

The direction of propagation is the direction of E x B.

Hence,

B = 1/C(6k-8i) cos [(6x+8z-10ct)]

B is in direction B = 1/C( 6k-8i)

and for this option E x B is along αi+βk

Answer 2

Answer:

Explanation:Exyjxz(,)cos()=+1068Ejikxizk=+⋅+1068cos[()()]=⋅10jKrcos[] Kik=+68; This is direction of waves travel i.e., direction of ‘C’ Direction of B will be alongCEik×=−+435Magnitude of B will be along CEik×=−+435Magnitude of BEcc==10 Bcikikc