JEE Main20264 April 2026Evening ShiftPhysicsElectromagnetic WavesActual
A magnetic field vector in an electromagnetic wave is represented by B =B₀ (2 vt- 2 x ) j . Its associated electric field vector is ______.
Options
- AE =-v B₀ (2 vt- 2 x ) k
- BE =-v B₀ (2 vt- 2 x ) i
- CE =v B₀ (2 vt- 2 x ) k
- DE =v B₀ (2 vt- 2 x ) i
Correct answer
A. E =-v B₀ (2 vt- 2 x ) k
Step-by-step solution
The direction of propagation of the electromagnetic wave is determined by the phase term 2 vt - 2 x , which indicates that the wave is travelling along the +x direction ( i ). The direction of the magnetic field B is given as j . In an electromagnetic wave, the direction of propagation is given by the direction of the cross product E B . Let the direction of the electric field E be n . n j = i Since (- k ) j = i , the direction of the electric field must be - k . The amplitude of the electric field is related to th