Q.

The electric field of an electromagnetic wave in free space is

E→=57 cos [7.5×106t–5×10–3(3x+4y)](4i^–3j^)N/C

The associated magnetic field in Tesla is:          [2025]

1 B→=573×108 cos [7.5×106t–5×10–3(3x+4y)](5k^)  
2 B→=573×108 cos [7.5×106t–5×10–3(3x+4y)](k^)  
3 B→=–573×108 cos [7.5×106t–5×10–3(3x+4y)](5k^)  
4 B→=–573×108 cos [7.5×106t–5×10–3(3x+4y)](k^)  

Ans.

(3)

E = CB

B = 57×53×108

3i^+4j^ is direction of propagation

⇒ (4i^–3j^)×(–k^)=4j^+3i^