In a plane electromagnetic wave travelling in free space,the electric field component oscillates sinusoidally at a frequency of $2.0 \times 10^{10} \text{ Hz}$ and amplitude $48 \text{ V m}^{-1}$. Then the amplitude of the oscillating magnetic field is: (Speed of light in free space $= 3 \times 10^8 \text{ m s}^{-1}$)

• A
  $1.6 \times 10^{-6} \text{ T}$
• B
  $1.6 \times 10^{-9} \text{ T}$
• C
  $1.6 \times 10^{-8} \text{ T}$
• D
  $1.6 \times 10^{-7} \text{ T}$