Question

The correct figure that shows, schematically, the wave pattern produced by superposition of two waves of frequencies 9Hz and 11Hz is?

Answer 1

Here, we should know that the superposition of two or waves is given by adding or subtracting the wave’s frequency, depending upon its direction of propagation and amplitude. Now, using this relation will help to find out the wave pattern produced by the superposition of the two waves.

Complete step-by-step answer:
Waves involve the transfer of energy without the transfer of matter. So, it can be said that, wave can be described as a disturbance that travels through a medium, transporting energy from one location to another location without transfer of matter.
Further, the frequency is defined as the number of waves that pass a fixed point in unit time. It can also be defined as the number of cycles or vibrations undergone during one unit of time.
Beat frequency is given by
$11Hz - 9Hz = 2Hz$
Also, beat is given by the same expression i.e., 2 Hz.
Although, the graph of oscillation is not given but the equation of the wave pattern produced by the superposition of the two waves of the given frequencies is given by:

Additional Information: Two waves are said to be coherent if they are moving with the same frequency and have constant phase difference.
The summation or adding or subtraction of all the waves travelling in a particular medium, gives us the superposition of waves. If the direction or amplitude of the waves are opposite then the superposition of waves is calculated by subtracting the waves, whereas if the two waves are travelling in the same direction or have same amplitude the resultant is given by adding up the two or more waves.
The S.I unit of frequency is Hertz or Hz and the unit of wavelength is meter or m. Furthermore we also know the S.I unit of time which is given by second or s.

Note: Superposition is calculated for two or more waves. The direction or amplitude of these waves will help in finding the resulting wave or the superposition of waves. A wave which has the same amplitude but opposite orientation will cancel out each other and thereby give zero output.