Answer:
the wave represents the second harmonic.
Explanation:
Given;
length of the cord, L = 64 cm
The first harmonic of a cord fixed at both ends is given as;
![f_o = \frac{V}{2L}](https://tex.z-dn.net/?f=f_o%20%3D%20%5Cfrac%7BV%7D%7B2L%7D)
The wavelength of a standing wave with two antinodes is calculated as follows;
L = N---> A -----> N + N ----> A -----> N
Where;
N is node
A is antinode
L = N---> A -----> N + N ----> A -----> N = λ/2 + λ/2
L = λ
The harmonic is calculated as;
![f = \frac{V}{\lambda} \\\\f = \frac{V}{L} = 2(\frac{V}{2L} ) = 2(f_o) = 2^{nd} \ harmonic](https://tex.z-dn.net/?f=f%20%3D%20%5Cfrac%7BV%7D%7B%5Clambda%7D%20%5C%5C%5C%5Cf%20%3D%20%5Cfrac%7BV%7D%7BL%7D%20%3D%202%28%5Cfrac%7BV%7D%7B2L%7D%20%29%20%3D%202%28f_o%29%20%3D%202%5E%7Bnd%7D%20%5C%20harmonic)
Therefore, the wave represents the second harmonic.
L = λ
The question is poorly worded, and makes it harder for the student to learn the basics of the subject. "Potential Difference" is the difference in electrical potential between two places in an electric field ... not in electrical potential energy.