Question

The direction of propagation of electromagnetic wave is along

• A. Electric field vector, \(\overrightarrow{E}\)
• B. Magnetic field vector, \(\overrightarrow{B}\)
• C. \(\overrightarrow{E}.\overrightarrow{B}\)
• D. \(\overrightarrow{E} \times \overrightarrow{B}\)

Hint:

Electromagnetic waves are transverse waves that consist of oscillating electric and magnetic fields perpendicular to each other and to the direction of wave propagation.

Answer 1

The Correct Option is D

The direction of propagation of the electromagnetic wave is perpendicular to the plane in which \(\overrightarrow{E}\) and \(\overrightarrow{B}\) lies. 

So, the direction of propagation of the electromagnetic wave E×B

\(\overrightarrow{E} \times \overrightarrow{B} = \overrightarrow{C}\)

Answer 2

Electromagnetic waves are formed by oscillating electric and magnetic fields. EM waves have magnitude as well as direction, so they are represented by a vector in space. 

Electromagnetic waves are generated, when an electric field interacts with a magnetic field. 

• Electromagnetic waves are vibrations occurring between an electric field and a magnetic field. 
• The electric field is the work done to bring a unit positive charge from infinity to a point in the field.
• The magnetic field is the work done to bring a north pole from infinity to a point in the field. 
• Electromagnetic waves can even travel in a vacuum.
• For example - light.

The electric field and magnetic field vibrate perpendicular to each other. The resultant electromagnetic waves are perpendicular to the direction of the electric field and magnetic field. Therefore, the magnetic field, electric field and electromagnetic waves oscillate perpendicular to each other.

Therefore, electromagnetic waves are given by-

\(\overrightarrow{M}=\overrightarrow{B}\times\overrightarrow{E}\)

• Here, \(\overrightarrow{M}\) = vector representing the electromagnetic waves
• \(\overrightarrow{B}\) = magnetic field vector
• \(\overrightarrow{E}\) = electric field vector

Therefore, electromagnetic waves are vector product of electric and magnetic field and its direction is perpendicular to them, \(\overrightarrow{M}=\overrightarrow{B}\times\overrightarrow{E}\)

Hence, the correct option is (D).

Answer 3

The direction of propagation of the electromagnetic wave tends to be perpendicular to the plane of not the electric as well as the magnetic field. 

So, option D is correct.

Electromagnetic waves are transverse waves that consist of oscillating electric and magnetic fields perpendicular to each other and to the direction of wave propagation. The direction of propagation of the wave is along the direction of the electric field vector and the magnetic field vector.