KVPY2020PhysicsMechanical Properties of Fluids
The platelets are drifting with the blood flowing in a streamline flow through a horizontal artery as shown below: Artery is contracted in region II . Choose the correct statement.
Options
- AAs the platelets enter a constriction, the platelets gets squeezed closer together in the narrow region and he
- BAs the platelets enter a constriction, pressure is lower there.
- CThe artery's cross section area is smaller in the constriction and thus the pressure must be larger there
- DPressure is same in all the parts of the artery
Correct answer
B. As the platelets enter a constriction, pressure is lower there.
Step-by-step solution
Using equation of continuity A 1 V 1 = A 2 V 2 where A 1 & A 2 are cross-section area of region I & region- II . as A 2 A 1 ⇒ V 2 > V 1 Using Bernouilli's equation P + 1 2 ρ V 2 = constant as V 2 > V 1 P 2 P 1 therefore pressure will be lower at constriction.