A carbon dioxide laser emits a sinusoidal electromagnetic wave that travel in vacuum in the negative X direction. The wavelength is 10.6 μ m and the E field is parallel to z-axis with E m a x = 1.5

Question

A carbon dioxide laser emits a sinusoidal electromagnetic wave that travel in vacuum in the negative X direction. The wavelength is 10.6 μ m and the E field is parallel to z-axis with E m a x ​ = 1.5 M V / m . Write vector equation of B as function of time and position.

TestHub · Accepted Answer

Wave is propagating in-ve x − direction ∵ E ^ × B ^ = V ^ K ^ × B ^ = − i ^ So B ^ = j ^ ​ B 0 ​ = C E 0 ​ ​ = 3 × 1 0 8 1.5 × 1 0 6 ​ = 5 × 1 0 − 3 T B = ( B 0 ​ j ^ ​ ) sin [ ω t + k x + ϕ ] Or B = ( B 0 ​ j ^ ​ ) cos [ ω t + kx + ϕ ] B = ( 5 × 1 0 − 3 j ^ ​ ) cos ( ω t + k x )

Physics - EM Waves Question with Solution | TestHub

Options:

Doubts & Discussion

JEE Main (2026)