| 1. | \(\left [ \dfrac{L}{T} \right ]\) | 2. | \(\left [ \dfrac{L^2}{T} \right ]\) |
| 3. | \(\left [ \dfrac{L}{T^2} \right ]\) | 4. | \(\left [ \dfrac{L^3}{T^2} \right ]\) |
| 1. | The terminal velocity is directly proportional to the square of the radius of the body. |
| 2. | The terminal velocity is inversely proportional to viscosity of the medium. |
| 3. | The terminal velocity is proportional to the difference of densities of body and fluid. |
| 4. | All of these |
| 1. | \(\dfrac{2}{9}\dfrac{{r}^{2}{\rho}{g}}{v}\) | 2. | \(\dfrac{1}{3}\dfrac{{r}^{2}{\rho}{g}}{v}\) |
| 3. | \(\dfrac{1}{9}\dfrac{{r}^{2}{\rho}{g}}{v}\) | 4. | \(\dfrac{1}{4}\dfrac{{r}^{2}{\rho}{g}}{v}\) |
Spherical balls of radius \(R\) are falling in a viscous fluid of viscosity with a velocity \(v.\) The retarding viscous force acting on the spherical ball is:
| 1. | directly proportional to \(R\) but inversely proportional to \(v.\) |
| 2. | directly proportional to both radius \(R\) and velocity \(v.\) |
| 3. | inversely proportional to both radius \(R\) and velocity \(v.\) |
| 4. | inversely proportional to \(R\) but directly proportional to velocity \(v.\) |
| 1. | the size of the raindrop |
| 2. | the viscosity of air |
| 3. | the acceleration due to gravity |
| 4. | all of the above |