Question

ब) श्यानता गुणांक से आप क्या समझते हैं ? श्यानता गुणांक ज्ञात
करने की 'ओस्टवाल्ड' विधि का वर्णन कीजिए।
3
What do you understand by Viscosity Coefficient ?
Describe 'Ostwald' method for determination of
viscosity coefficient.​

Answer 1

Viscosity Coefficient can be defined as the degree of resistance to the flow of a fluid under the application of a force.

• Its value is constant for a specific liquid.
• Viscosity= shear stress/ shear rate

Ostwald method for the determination of viscosity coefficient:-

• It employs a U-shaped viscometer which measures the viscosity of liquid whose density is known.
• Basically, the time taken for a known volume of a liquid to flow through the viscometer is measured and values are put into the formulae:-

             n1 =n2,

             ρ1t1 = ρ2t2

(where n1 and n2 are viscosity coefficients of the liquid and water and  ρ1 and ρ2 are densities of liquid and water respectively)