Question

Which of the following statements does not correctly describe a harmonic plane wave traveling in some medium.

Answer 1

Answer:

Incorrect statement is (b).

Explanation:

Option (a) : There is an inverse relation between the time and the frequency. The time taken depends on the frequency of the number of oscillations. Statement 1 is correct i.e. the time taken by any point of the wave to make one complete oscillation does not depend on the amplitude.

Option (b) : Speed of a wave is given by the product of its frequency and wavelength. It is not necessary that doubling the wavelength of the wave will halve its frequency as speed depends on the medium.

Option (c) : Doubling the amplitude has no effect on on the wavelength as amplitude does not depends on its wavelength.

Option (d) : Since, $v=f\times \lambda$

Speed is directly proportional to the frequency and wavelength. So, doubling the frequency of the wave will double its speed. So, the incorrect statement is (b).