
| 1. | As the platelets enter a constriction, the platelets get squeezed closer together in the narrow region and hence the fluid pressure must rise there. |
| 2. | As the platelets enter a constriction, pressure is lower there. |
| 3. | The artery's cross-section area is smaller in the constriction and thus the pressure must be larger there because pressure equals the force divided by area. |
| 4. | The pressure is the same in all the parts of the artery. |
Water containing air bubbles flows without turbulence through a horizontal pipe which has a region of a narrow cross-section. In this region the bubbles:
| 1. | move with greater speed and are smaller than in the rest of the pipe. |
| 2. | move with greater speed and are larger in size than in the rest of the pipe. |
| 3. | move with lesser speed and are smaller than in the rest of the pipe. |
| 4. | move with lesser speed and are of the same size as in the rest of the pipe. |
