University:
North Idaho College
Course:
PHYS-211 | Engineering Physics I
Academic year:

2023
Views:

379

Pages:

4
Author:

Hani T.

Measurement of Viscosity The Rate of laminar flow through a capillary at Constant pressure is related to the viscosity of the Liquid η = (π * r^4 * t * P) / (8 * V * L) where r is radius of capillary t is time taken for the flow V is the volume of liquid flowing in time t L is the length of the capillary P is pressure driving the flow Since P = h.d.g where h is the height of the liquid column, d is the density and g is the acceleration due to gravity, Replacing for P, we get... h = (π * h * d * g * r^4 * t) / (8 * η * L * V) If equal volumes of two liquids are allowed to flow through the same capillary under similar conditions, If d1, d2, t1, t2 and one of the two viscosities are known, the other can be calculated. The Time of flow of liquid 1 with a density d1 (volume A to B) through the capillary (B-D) is measured using a stop watch. using the same viscometer the time of flow for liquid 2 with density d2 is also determined. All measurements were carried out at the same temperature by keeping the viscometer in a thermostat. for the above method to work, one of liquids must have a known viscosity.