Electromagnetic Waves Question 4
Question 4 - 2024 (29 Jan Shift 2)
A plane electromagnetic wave of frequency $35 \mathrm{MHz}$ travels in free space along the X-direction. At a particular point (in space and time) $\overrightarrow{\mathrm{E}}=9.6 \mathrm{j} \hat{V} / \mathrm{m}$. The value of magnetic field at this point is :
(1) $3.2 \times 10^{-8} \mathrm{kT}$
(2) $3.2 \times 10^{-8} \mathrm{i} \hat{\mathrm{T}}$
(3) $9.6 \hat{\mathrm{j}} \mathrm{T}$
(4) $9.6 \times 10^{-8} \mathrm{k} \hat{\mathrm{T}}$
Show Answer
Answer: (1)
Solution:
$\frac{E}{B}=C$
$\frac{E}{B}=3 \times 10^{8}$
$B=\frac{E}{3 \times 10^{8}}=\frac{9.6}{3 \times 10^{8}}$
$B=3.2 \times 10^{-8} \mathrm{~T}$
$\hat{B}=\hat{v} \times \hat{E}$
$=\hat{i} \times \hat{j}=\hat{k}$
So,
$\overrightarrow{\mathrm{B}}=3.2 \times 10^{-8} \hat{\mathrm{k}} \mathrm{T}$
