1 Answers

Option 4 : 4 and 5

Explanation:

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Ideal fluid:

  • A fluid that is incompressible and is having no viscosity is known as an ideal fluid.
  • Ideal fluid is an imaginary fluid as all the fluids, which exist, have some viscosity.

Real fluid:

  • A fluid that possesses viscosity, is known as real fluid.
  • All the fluid in practice is real fluids.

Newtonian fluid:

  • Fluids for which shear stress (τ) is directly proportional to the deformation rate or velocity gradient are Newtonian fluid.

Non-Newtonian fluid:

  • Fluids for which shear stress (τ) is not directly proportional to the deformation rate or velocity gradient are non-Newtonian fluid.

Pseudoplatsic (n < 1): 

  • Fine particle suspension, gelatine, blood, milk, paper pulp, polymeric solutions such as rubbers, paints.

Dilatant fluids (n > 1): 

  • Ultrafine irregular particle suspension, sugar in water, aqueous suspension of rice starch, quicksand, butter printing ink.

Ideal plastics or Bingham plastic fluids:

  • Sewage sludge, drilling muds, toothpaste.

Thixotropic and rheopectic fluid:

  • Thixotropic fluids are liquids or gases whose viscosity decreases upon applying stress over a known time period.
  • Therefore, it can be defined as a time-dependent pseudoplastic behaviour. 
  • In contrast, the behaviour of rheopectic fluids can be described as time-dependent dilatant behaviour
  • Printer’s ink, crude oil, lipstick, certain paints and enamels
  • Very rare liquid-solid suspensions, gypsum suspension in water and bentonite solutions.

Viscoelastic fluids: 

  • Liquids solid combination in pipe flow, bitumen, tar, asphalt, polymerized fluids with drag reduction features.
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