Question

For superposition of two waves, the following is correct

• A. They must have the same frequency and wavelength
• B. they must have equal frequencies but may have unequal wavelengths
• C. they must have the same wavelength but may have different frequencies
• D. they may have different wavelength and different frequencies

Answer 1

Answer: (D)

Principle of superposition states that the displacement of two waves
$y_{1}=f _{1}\left( t -\frac{ x }{ v }\right)$ and $y _{2}= f _{2}\left( t +\frac{ x }{ v }\right)$ is $y = y _{1}+ y _{2}$
Wavelength and frequency depend on the function $f _{1}$ and $f _{2}$
$\therefore $ They can have any wavelength and any frequency