Question: In a plane electromagnetic wave travelling in free space, the electric field component oscillates sinusoidally at a frequency of $2.0 \times 10^{10} \mathrm{~Hz}$ and amplitude $48 \mathrm{Vm}^{-1}$. Then the amplitude of oscillating magnetic field is : (Speed of light in free space $=3 \times 10^8 \mathrm{~m} \mathrm{~s}^{-1}$ ): (NEET-2023)
A) $1.6 \times 10^{-8} \mathrm{~T}$
B) $1.6 \times 10^{-7} \mathrm{~T}$
C) $1.6 \times 10^{-6} \mathrm{~T}$
D) $1.6 \times 10^{-9} \mathrm{~T}$
Answer: $1.6 \times 10^{-7} \mathrm{~T}$
Explanation
$C=\frac{E_0}{B_0} $
$\mathrm{~B}_0=\frac{\mathrm{E}_0}{\mathrm{C}}$
$=\frac{48}{3 \times 10^8}$
$=1.6 \times 10^{-7} \mathrm{~T}$
