An electromagnetic wave propagating through free space is described by the following equations:
\( E = E_{0}\sin(kz - \omega t) \)
\( B = B_{0}\sin(kz - \omega t) \)
for such a wave, pick the correct equation.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → \( E_{0}k = B_{0}\omega \)
In an electromagnetic wave, the ratio of the field amplitudes equals the speed of the wave. For a wave \( \sin(kz - \omega t) \), that speed is \( \omega/k \).
\( \displaystyle \frac{E_{0}}{B_{0}} = c = \frac{\omega}{k} \)
Cross-multiplying:
\( E_{0}k = B_{0}\omega \)
Note: A similar question was also asked in CUET (UG) 2026 on 25-05-2026 (Slot 1) and on 20-05-2026 (Slot 2), and in CUET (UG) 2023 on 02-07-2023 (Slot 3) and on 14-06-2023 (Slot 1).