Electromagnetic Waves | JEE Main 2025 Solution

JEE MAIN 2025

23-01-2025 SHIFT-1

Question

The electric field of an electromagnetic wave in free space is $\overrightarrow{\mathrm{E}}=57 \cos \left[7.5 \times 10^6 \mathrm{t}-5 \times 10^{-3}(3 x+4 y)\right](4 \hat{i}-3 \hat{j}) N / C$.
The associated magnetic field in Tesla is

Select the correct option:

$\overrightarrow{\text{B}}=\frac{{57}}{{3\times {{{10}}^{8}}}}\cos \left[ {7.5\times {{{10}}^{6}}\text{t}-5\times {{{10}}^{{-3}}}(3x+4y)} \right](5\hat{k})$

$\overrightarrow{\text{B}}=\frac{{57}}{{3\times {{{10}}^{8}}}}\cos \left[ {7.5\times {{{10}}^{6}}\text{t}-5\times {{{10}}^{{-3}}}(3x+4y)} \right](\hat{k})$

$\overrightarrow{\text{B}}=-\frac{{57}}{{3\times {{{10}}^{8}}}}\cos \left[ {7.5\times {{{10}}^{6}}\text{t}-5\times {{{10}}^{{-3}}}(3x+4y)} \right](5\hat{k})$

$\overrightarrow{\text{B}}=-\frac{{57}}{{3\times {{{10}}^{8}}}}\cos \left[ {7.5\times {{{10}}^{6}}\text{t}-5\times {{{10}}^{{-3}}}(3x+4y)} \right](\hat{k})$

✓ Correct! Well done.

✗ Incorrect. Try again or view the solution.

Solution