Question

In an electromagnetic wave, the oscillating electric and magnetic field vectors are oriented in

• A. mutually perpendicular directions with a phase difference of π/2
• B. the same direction and in the same phase
• C. mutually perpendicular directions and are in phase
• D. the same direction with a phase difference of π/2
• E. mutually perpendicular directions with a phase difference of π

Answer 1

The Correct Option is C

In an electromagnetic wave, the electric field vector (\( \vec{E} \)) and the magnetic field vector (\( \vec{B} \)) oscillate in mutually perpendicular directions and are in phase with each other. This means that the electric and magnetic fields reach their maximum and minimum values simultaneously, without any phase difference between them.

The general characteristics of an electromagnetic wave are:

• The electric field (\( \vec{E} \)) and magnetic field (\( \vec{B} \)) are mutually perpendicular to each other.
• The electric and magnetic fields are also perpendicular to the direction of propagation of the wave.
• The electric and magnetic fields oscillate in phase, meaning they reach their maximum and minimum values at the same time.

Thus, the correct description of the orientation and phase of the electric and magnetic field vectors in an electromagnetic wave is:

Correct Answer:

Correct Answer: (C) Mutually perpendicular directions and are in phase

Answer 2

In an electromagnetic wave, the electric and magnetic field vectors are always **mutually perpendicular** and oscillate in phase with each other.  
This means that the electric field vector oscillates in one plane and the magnetic field vector oscillates in a perpendicular plane, both at the same frequency.  
Furthermore, the electric and magnetic fields are in phase, meaning their peaks and zero crossings occur simultaneously.

This characteristic holds true for all electromagnetic waves, including light waves, radio waves, etc.  
The correct configuration is that the electric and magnetic fields are perpendicular to each other and to the direction of wave propagation.