Which of the following is NOT true about electromagnetic waves?

The correct answer is Option (2) → \( B_0/E_0=c \)

Option (1) They propagate perpendicular to both the electric and magnetic fields. — True. In an electromagnetic wave \( \vec{E} \) and \( \vec{B} \) are perpendicular to each other and to the direction of propagation.

Option (2) \( B_0/E_0=c \) — Not true. The field amplitudes are related by \( B_0=E_0/c \). So \( E_0/B_0 \) equals \( c \). The ratio \( B_0/E_0 \) is \( 1/c \), about \( 3.3\times10^{-9}\,\mathrm{s\,m^{-1}} \).

Option (3) They carry momentum. — True. The electromagnetic field carries momentum. For light, each quantum of energy \( h\nu \) carries momentum \( h\nu/c \).

Option (4) They carry energy. — True. Light carries energy from the sun to the earth, and radio and TV signals carry energy from the broadcasting stations.

NCERT (2026-27):
Nature of Electromagnetic Waves – “… It is also seen from Maxwell’s equations that the magnitude of the electric and the magnetic fields in an electromagnetic wave are related as

    \( B_0=(E_0/c) \)\( \qquad (8.10) \)”