Question

Consider an electromagnetic wave propagating in vacuum. Choose the correct statement :

• A. For an electromagnetic wave propagating in $+y$ direction the electric field is $\vec{E}=\frac{1}{\sqrt{2}} E_{y z}(x, t) \hat{z}$ and the magnetic field is $\vec{ B }=\frac{1}{\sqrt{2}} B _{ z }( x , t ) \hat{ y }$
• B. For an electromagnetic wave propagating in $+y$ direction the electric field is $\vec{E}=\frac{1}{\sqrt{2}} E_{y z}(x, t) \hat{y}$ and he magnetic field is $\vec{ B }=\frac{1}{\sqrt{2}} B _{ yz }( x , t ) \hat{ z }$
• C. For an electromagnetic wave propagating in $+ x$ direction the electric field is $\vec{ E }=\frac{1}{\sqrt{2}} E _{ yz }( y , z , t )(\hat{ y }+\hat{ z })$ and the magnetic field is $\vec{ B }=\frac{1}{\sqrt{2}} B _{ yz }( y , z , t )(\hat{ y }+\hat{ z })$
• D. For an electromagnetic wave propagating in $+x$ direction the electric field is $\vec{E}=\frac{1}{\sqrt{2}} E_{y z}(x, t)(\hat{y}-\hat{z})$ and eh magnetic field is $B =\frac{1}{\sqrt{2}} B _{ yz }( x , t )(\hat{ y }+\hat{ z })$

Answer 1

Answer: (D)

If wave is propagating in $x$ direction, $\vec{E} \,\& \,\vec{B}$ must be functions of $(x, t) \&$ must be in $y-z$ plane.