Two massless springs of spring constant $$\mathrm{K}_1$$ and $$\mathrm{K}_2$$ are connected one after the other forming a single chain, suspended vertically and certain mass is attached to the free end. If '$$e_1$$' and '$$e_2$$' are their respective extensions and '$$\mathrm{f}$$' is their stretching force, the total extension produced is

The extension in a wire obeying Hooke's law is $$x$$. The speed of sound in the stretched wire is $$v$$. If the extension in the wire is increased to $$4 x$$, then the speed of sound in a wire is

The density of a metal at normal pressure $$p$$ is $$\rho$$. When it is subjected to an excess pressure, the density becomes $$\rho^{\prime}$$. If $$K$$ is the bulk modulus of the metal, then the ratio $$\frac{\rho^{\prime}}{\rho}$$ is

Two rods of same material and volume having circular cross-section are subjected to tension $$T$$. Within the elastic limit, same force is applied to both the rods. Diameter of the first rod is half of the second rod, then the extensions of first rod to second rod will be in the ratio