Discussion
Which one of the following measures of viscosity is dimensionless?
Answer: D
The dimensionless measure is specific viscosity.
Specific viscosity is the fractional increase in viscosity that the dissolved polymer causes, \(\eta_{sp} = (\eta - \eta_{s})/\eta_{s}\), a ratio of two viscosities, so its units cancel.
The others carry units. Reduced viscosity is \(\eta_{sp}/c\) and inherent viscosity is \(\ln(\eta_{rel})/c\); dividing by the concentration c gives both units of volume per mass, such as dL/g. Zero-shear viscosity is an actual viscosity, the limiting value at vanishing shear rate, measured in Pa s.
Relative viscosity \(\eta/\eta_{s}\) is the other dimensionless member of the family, but it is not among the options.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development