A plane electromagnetic wave of frequency 25MHz  travels in free space along the x-direction . At a particular point in the space and time, if the intensity of electric field E→=6.3j^ V/m, the magnetic induction B→ at this point is

1. GivenWave Frequency  =25 MHzIntensity of Electric Field E¯=6.3j^ V/mThe magnitude of the magnetic field is given byB=Ec=6.33×108=2.1×10−8 T. 2. The vector  E→×B→ should be along  x-direction, and soj^×A^=i^,  indicates that  A^=k^.Thus,  B→=2.1×10−8k^ T.Therefore, the correct answer is (C).