If the plane of vibrations of the string is changed randomly in a very short intervals of time, it is known as

Options

A. polarised wave
B. plane polarised wave
C. unpolarised wave
D. Both (a) and (b)

Answer

C

Explanation

We can consider the vibration of the string in the xz-plane generating a z-polarised wave whose displacement will be given by
`z(x,t)=asin(kx-omegat)" "....(iii)`
It should be mentioned that the linearly polarised waves i.e. the displacement of each point of the string is always at right angles to the direction of propagation of the wave.
Finally, if the plane of vibration of the string is changed randomly in very short intervals of time, then we have what is known as an unpolarised wave.
Thus, for an unpolarised wave, the displacement will be randomly changing with time though it will always be perpendicular to the direction of propagation.