An electromagnetic wave has an electric field given by $\vec { E } = - \left( 9.0 \times 10 ^ { 5 } \mathrm {~V} / \mathrm { m } \right) \hat { j } \cos \left[ \left( 9.42 \times 10 ^ { 15 } \mathrm { rad } / \mathrm { s } \right) t - k z \right]$ . The direction the wave is traveling in is
A) $\hat { k }$
B) $\hat { j }$
C) - $\hat { j }$

D) $\hat { i }$

Question

An electromagnetic wave has an electric field given by $\vec { E } = - \left( 9.0 \times 10 ^ { 5 } \mathrm {~V} / \mathrm { m } \right) \hat { j } \cos \left[ \left( 9.42 \times 10 ^ { 15 } \mathrm { rad } / \mathrm { s } \right) t - k z \right]$ . The direction the wave is traveling in is
A) $\hat { k }$
B) $\hat { j }$
C) - $\hat { j }$

D) $\hat { i }$

Quizplus · Accepted Answer

The direction of an electromagnetic wave is given by the direction of propagation, which can be determined from the wave equation. In this case, the wave equation includes a term $-kz$, indicating that the wave is propagating in the $+z$ direction, which corresponds to $\hat { k }$.

An Electromagnetic Wave Has an Electric Field Given By the Direction the Wave Is Traveling in Is A)

An Electromagnetic Wave Has an Electric Field Given By the Direction the Wave Is Traveling in Is
A)