-12, No-2, June-2012
marble), yielded more accurate value of viscosity (9.8 Poise) compared to the value obtained
from the other two spheres. Therefore, perfectness of the spherical shape is very important
for this experiment. To verify this, the experiment was repeated with a steel ball bearing
which gave the value of viscosity as 10.0 Poise. In the case of the steel ball, the time taken
for travelling the distance of 0.4m is 0.377s.
The value of viscosity obtained (6.8 Poise) employing smaller diameter (38mm) acrylic tube
is also not accurate. Hence spherical shape and large diameter tubes are necessary for
accurate viscosity measurements.