Answer:
D. 550 Hz
Explanation:
Frequency for string is given by
[tex]f_{} =\frac{v}{2L}[/tex]
where v is the speed of the wave, L = m is the length
Frequency is inversely proportional to the Length of the string
[tex]f \alpha \frac{1}{L} \\[/tex]
from above relation we can write
[tex]\frac{f_{1}}{f_{2}} =\frac{L_{2}}{L_{1}}[/tex]
The newly shortened string has 4/5 the length of the full string .i,e
[tex]\frac{440}{f_{2}} =\frac{\frac{4}{5}L_{1} }{L_{1}}\\f_{2}=\frac{440\times5}{4} \\f_{2}=550 Hz[/tex]
Hence option D is correct