Question 148: EM waves

Question

A plane polarized monochromatic EM wave is traveling in vacuum along z direction such that at t = t
1
it is found that the electric field is zero at a spatial point z
1
. The next zero that occurs in its neighbourhood is at z
2
. The frequency of the electroagnetic wave is :

Accepted Answer

Since $$c = f\lambda  \Rightarrow f = {c \over \lambda }$$. Here, $$\lambda  = 2|{z_2} - {z_1}|$$ and $$c = 3 	imes {10^8}$$. Therefore,
$$f = {{3 	imes {{10}^8}} \over {2|{z_2} - {z_1}|}} = {{1.5 	imes {{10}^8}} \over {|{z_2} - {z_1}|}}$$

Answer

$${{3 	imes {{10}^8}} \over {\left| {{z_2} - {z_1}} ight|}}$$

Answer

$${{1.5 	imes {{10}^8}} \over {\left| {{z_2} - {z_1}} ight|}}$$

Answer

$${{6 	imes {{10}^8}} \over {\left| {{z_2} - {z_1}} ight|}}$$

Answer

$${1 \over {{t_1} + {{\left| {{z_2} - {z_1}} ight|} \over {3 	imes {{10}^8}}}}}$$

EM waves

A plane polarized monochromatic EM wave is traveling in vacuum along z direction such that at t = t 1 it is found that the electric field is zero at a spatial point z 1 . The next zero that occurs in its neighbourhood is at z 2 . The frequency of the electroagnetic wave is :

Choose the correct answer: