Question

Energy is not carried by which of the following waves
A. stationary
B. progressive
C. transverse
D. electromagnetic

Answer 1

Hint: In order to transport energy, there needs to be a net flow of energy in a certain direction due to the wave. Out of the given options, the type of waves which do not cause net flow of certain direction cannot carry energy.

Complete answer:
A stationary wave is formed when two progressive waves travelling in opposite directions interfere with each other.

Consider two waves having the same amplitude and frequency travelling towards each other as shown in the diagram.
When they reach each other, they undergo interference where they superimpose on each other. The resultant of this type of superimposition is the stationary waves. As the name implies, they are not travelling but stay stationary.
These two waves carry equal amounts of energy but in opposite directions and after they superimpose, the net energy comes out to be zero. Hence, the stationary waves cannot carry energy with them.

Therefore, based on the above discussion the correct answer is option A.

Additional information:

These diagrams show the resultant stationary waves formed when incident and reflected waves superimpose at different phase angles.
The waves are stationary because they are formed by two waves having equal motion but in opposite directions. The equal and opposite nature of two waves results in stationary nature of the stationary waves. This phenomenon is observed when incidents and reflected waves superimpose on each other.

Note:
The electromagnetic waves are transverse waves which can form both progressive waves and the stationary waves. The stationary waves are formed when electromagnetic waves get reflected from an obstruction and interfere with each other.