Class 11 NEET Physics Properties of Matter Questions

Concept:Terminal velocity of a sphere in a liquid depends on the density difference between the sphere and the liquid. For constant radius and viscosity, terminal velocity varies linearly with the ratio of densities.Explanation:Use the standard formula for terminal velocity: $V_T = \frac{2 r^2 g}{9 \eta} (\sigma - \rho)$.Rewrite it as $V_T = \frac{2 r^2 g \rho}{9 \eta} \left( \frac{\sigma}{\rho} - 1 \right)$.This is of the form $V_T = k \left( \frac{\sigma}{\rho} - 1 \right)$, where $k$ is a positive constant for the given setup.So $V_T$ vs $\frac{\sigma}{\rho}$ is a straight line with positive slope $k$ and an intercept of $-k$ on the $V_T$-axis.Thus the line passes through the point $\left(1, 0\right)$ and has a negative intercept when extended to $\frac{\sigma}{\rho}=0$.Answer:The graph is a straight line with positive slope and negative intercept on the vertical axis, starting from $\left(1, 0\right)$. The correct option shows this linear variation.