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Question:

A plane electromagnetic wave of frequency 50MHz travels in free space along the positive x-direction. At a particular point in space and time, →E=6.3^jV/m. The corresponding magnetic field →B, at that point will be:

6.3×10⁻⁸^kT

18.9×10⁸^kT

18.9×10⁻⁸^kT

2.1×10⁻⁸^kT

Solution:

The correct option is C
2.1×10⁻⁸^kT
|B|=|E|/C=6.3×10⁸/3×10⁸=2.1×10⁻⁸T
and ^E × ^B = ^C
^j × ^B = ^i
^B = ^k
→B=|B|^k=2.1×10⁻⁸^kT