What are stationary waves state the necessary conditions for the formation of stationary waves write any 2 characteristics of stationary waves?

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Production of Stationary Waves
Nodes and Antinodes
Formation of Stationary Waves
Practical Example of Stationary Waves
Stationary Waves FAQs

Condition for propagation of Stationary Waves

Stationary waves can form under a variety of conditions, but they are easily demonstrated in a medium which is finite or bounded. It can be produced for both transverse and longitudinal waves. If two ends of a string are fastened straight and if, at a point, is pulled perpendicular to the length, and released, then transverse wave will be generated in the string. This wave after reflecting at the two closed ends will come back and superpose with the principal wave. After some time these two waves will also stop. This type of wave is called stationary wave.

Stationary waves are produced on the following condition:

(1) Two identical waves travelling opposite to each other are needed to superimpose on each other.

(2) The two waves are needed to approach each other with the same speed.

(3) Wave surface contracts in horizontal position.

(4) Wave crest expands in wave position.

(5) At each point displacement of the two waves must be equal and opposite.

(6) Amplitudes of the two waves must be same.

(7) Wavelengths of the two waves must be same.

(8) The reflected wave has to have the same amplitude and frequency as the incoming wave.

(9) The losses of energy at the reflecting surfaces and elsewhere can be made up by the energy supplied by a driver eg. a bow, musician blowing air, etc and this will maintain the stationary wave.

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A Stationary Waves are defined as a combination of two waves having equal amplitude and frequency but moving in opposite directions.

A standing wave is formed due to interference. Specifically, a standing wave is a wave that oscillates in time but its peak altitude profile does not move in space. When waves are superimposed, their energies are either canceled out or added together. Stationary wave is also known as a standing wave.

Production of Stationary Waves

Suppose if we pluck a string on a guitar, the vibrations are created within the body of the guitar, which is also known as mechanical waves. This vibrating instrument produces sound because the energy produced through these vibrations moves through the air and reaches our ears. The vibrations created are known as standing waves or stationary waves.

Stationary waves can be created only when their motion is restricted to a given, finite region.

Nodes and Antinodes

Each standing wave pattern has points along with the medium that appears to be standing still. Such points are known as nodes. There are also certain points along with the medium which undergoes maximum displacement during every vibrational cycle of the standing wave. Such points are called antinodes.

Formation of Stationary Waves

The picture below describes two waves moving through a medium in opposite directions. Let’s assume the blue wave is moving to the right and the green wave is moving towards the left. When two waves meet while moving along the same medium, interference takes place. The blue and green waves interfere to form a new wave pattern which is known as the resultant wave. The resultant is actually the result of two individual waves in accordance with the principle of superposition.

The resultant wave is a new wave pattern known as a standing wave pattern.

These waves are produced when two waves of the same frequency interfere with one another while traveling in opposite directions. This is how standing waves are formed.

The wave patterns are characterized by some fixed points which undergo no displacement. These points are known as nodes. In the above figure, the position of nodes is denoted by N.

Also, there are certain points that undergo maximum displacement. These points are present in between the consecutive nodal points. The position of antinodes is denoted by AN. These points oscillate back and forth between the maximum positive displacement and maximum negative displacement.

Practical Example of Stationary Waves

If two people shake a jump rope, the pattern of waves it forms is quite similar to standing or stationary waves.

This was all about the concept of standing or stationary waves. Get some practice of the same on our free Testbook App. Download Now!

Stationary Waves FAQs

Ans.1 Stationary waves are two opposing waves with the same amplitude and frequency.

Ans.2 Two waves of identical wavelengths and amplitude moving in opposite directions generate stationary waves.

Ans.3 Stationary waves do not move in any directionAmplitude varies for different particles All particles in a loop are in the same phase & they are in opposite phase with respect to the adjacent loop.

There is no flow of energy.

Ans.4 Nodes are points in a stationary wave when a particle’s amplitude of vibration is zero. Whereas, Antinodes are points in a stationary wave where a particle’s amplitude of vibration is highest.

Ans.5 Progressive waves transfer energy from one place to another. Stationary waves, on the other hand, do not transfer energy. Hence, they are not progressive.