At what temperature will the speed of sound be double of its value at $0^{\circ }C$ ?

$T_1=273,v_2=2V_1,$

$V_1=v,T_2=?$

We know that $V\frac{a}{T}$

$\frac{T_2}{T_1}=\frac{V_2^2}{V_1^2}$

$\Rightarrow T_2=273\times (2{)}^2$

$=4\times 273K$

So temperature will be $4\times 273={819}^{\circ }C$