Question

Atherosclerosis is a disease for which an artery is narrowed by plaque, leading to a reduced aperture over a length of less than 1 cm. For this, how many of the following statements are correct? Answer 0, 1, 2, 3, 4 or 5.

i) From a consideration of kinetic energy conservation only, Bernoulli's law can show that the blood pressure is unchanged between positions before and after the reduced aperture i.e., positions that contain no plaque.

ii) Poiseulle's law derives from an understanding that kinetic energy is lost to heat.

iii) If Reynold's number is greater than 200 in a tube, then the flow must be turbulent.

iv) Poiseulle's law applies for laminar flow only.

v) Bernoulli's law applies for horizontal tubes only

Answer 1

(i) True,

If there is no change in aperture, there is no change in speed of the fluid, Since, aperture is same before and after the plaque region, hence pressure remains same.

(ii) True,

Energy loss due to friction is depicted by Poiseulle's law

(iii) False,

When Reynold's number is less than 2000 in a tube, then the flow is laminar and if it is greater than 2000, flow is turbulent.

(iv) True

(v) False

Bernoulli's therem is based on conservation of energy. hence it is applicable in vertical as well as horizontal flow