Question

A plane electromagnetic wave of frequency $28MHz$ travels in free space along the positive x-direction. At a particular point in space and time, electric field is $9.3V/m$ along positive y-direction. The magnetic field (in T) at that point is

• A. $3.1\times {10}^{-8}$ along positive z-direction
• B. $3.1\times {10}^{-8}$ along negative z-direction
• C. $3.2\times {10}^7$ along positive z-direction
• D. $3.2\times {10}^7$ along negative z-direction

Answer 1

The correct option is A $3.1\times {10}^{-8}$ along positive z-direction

$B=\frac{E}{C}=\frac{9.3}{3\times {10}^8}=3.1\times {10}^{-}8$