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Class 9, Science, Chapter-11, Lecture-2, Types of Waves (Notes)

WAVE PULSE:

A disturbance which is confined to a small part of the medium at any given time is called wave pulse.

PERIODIC WAVE:

A wave in which the particles of the medium repeat their motion after a fixed interval is called a periodic wave.

Differences Between:

Wave Pulse

Periodic Wave

1. It is a wave of short duration.

1. It is a continuous wave of long duration.

2. It is not repetitive

2. It is repetitive

3. It is set by a single disturbance.

3. It is set up by continuous disturbance.

4. The medium oscillates for a short time.

4. The medium oscillates for long time.

5. It is confined to a small part.

5. It is stretched over entire length of the medium.

PHASE:

All the points on a wave which are in the same state of vibration are said to be in phase with respect to one another.

WAVE QUANTITY:

The quantity related to the medium which changes its value at a position with time and has different values at different positions at a given time is termed as Wave Quantity.

Example: 

Wave quantity of Sound Wave is Density of air
Wave quantity of Water Wave is Distance from the line of zero displacement
Wave quantity of Light Wave is Strength of electric field and magnetic field
Wave quantity of longitudinal wave on a slinky is Density of coils