In an electromagnetic wave, the amplitude of magnetic field is \( 1.1\times10^{-6}\,\mathrm{T} \). What is the amplitude of electric field?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → \( 330\,\mathrm{N\,C^{-1}} \)
In an electromagnetic wave in free space the amplitudes of the electric and magnetic fields are related through the speed of light, \( \frac{E_0}{B_0} = c \).
\( E_0 = cB_0 = 3\times10^{8}\,\mathrm{m\,s^{-1}}\times1.1\times10^{-6}\,\mathrm{T} \)
\( E_0 = 3.3\times10^{2}\,\mathrm{N\,C^{-1}} = 330\,\mathrm{N\,C^{-1}} \)
Note: NTA picked this question from an NCERT (2026-27) exercise and changed the figures. Do not ignore NCERT while practising numericals.
NCERT (2026-27):
Exercises – …
