JEE Main 2025 Jan 29 Shift 1, Physics Q14: Wave Nature of Matter

For a non-relativistic particle, $\lambda =\frac{h}{p}=\frac{h}{\sqrt{2mK}}.$ Squaring and inverting:

${\lambda }^2=\frac{h^2}{2m}\cdot \frac{1}{K}⟺\frac{1}{K}=\frac{2m}{h^2}{\lambda }^2.$

So a plot of $1/K$ against $\lambda$ is a parabola opening upward through the origin, with slope-related constant $2m/h^2.$ This corresponds to option (2).