Q.

The electric field in an electromagnetic wave is given by E=i^40cosω(t-zc) NC-1.  The magnetic field induction of this wave is (in SI unit):      [2024]

1 B=j^40cosω(t-zc)  
2 B=k^40ccosω(t-zc)  
3 B=i^40ccosω(t-zc)  
4 B=j^40ccosω(t-zc)  

Ans.

(4)

E=40cos(ωt-ωcz) NC-1i^

E is along +x direction

v is along +z direction

and Direction of c^ must be along E×B.

So direction of B will be along +y and magnitude of B will be E0c.

B0=E0c=40c