Physics - Sound Wave Question with Solution | TestHub

Suppose $n_p=$ frequency of piano $=$ ? $\left(n_p\propto \sqrt{T}\right)$ ${\mathrm{n}}_{\mathrm{f}}=$ frequency of tuning fork $=512\mathrm{Hz}$ $\mathrm{x}$ = Beat frequency $=4$ beats $/\mathrm{s}$, which is decreasing $(4\to 2)$ after changing the tension of piano wire. Also, tension of piano wire is increasing so $n_p\uparrow$ Hence, ${\mathrm{n}}_{\mathrm{p}}\uparrow -{\mathrm{n}}_{\mathrm{f}}=\mathrm{x}\downarrow ⟶$ wrong ${\mathrm{n}}_{\mathrm{f}}-{\mathrm{n}}_{\mathrm{p}}\uparrow =\mathrm{x}\downarrow ⟶$ correjct $\Rightarrow {\mathrm{n}}_{\mathrm{p}}={\mathrm{n}}_{\mathrm{f}}-\mathrm{x}=512-4=508\mathrm{Hz}$