Q. The electric and the magnetic field, associated with an e.m. wave, propagating along the +z-axis, can be represented by
A) E⃗ = E₀ĵ, B⃗ = B₀k̂
B) E⃗ = E₀î, B⃗ = B₀ĵ
C) E⃗ = E₀k̂, B⃗ = B₀î
D) E⃗ = E₀ĵ, B⃗ = B₀î
Explanation
[Solution from source] An EM wave travels along E⃗ × B⃗, with E and B perpendicular to each other and to the propagation direction. With E along î and B along ĵ, î × ĵ = k̂, i.e. +z. E along ĵ with B along î gives ĵ × î = −k̂, the reverse direction. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.