Basics-Fluid Mechanics and Machinery Part-I

Most important ONE LINER QUESTIONS-ANSWERS on Basics Fluid Mechanaics.It helps in quick revision and competitive exams

• A substance unable to resist even the slightest amount of shear without flowing - Fluids
• Properties of fluid capable of flowing conforms to shape of containing vessel ( no resistance change of shape) deforms continuously it is subjected to even a smallest shear stress. 
• Ideal fluid having - Zero friction (frictionless),  inviscous, incompressible. 
• Real fluid having - internal friction. 
• Practical fluids are - Compressible, posses surface tension, viscous. 
• A real fluid in which the rate of defamation is directly proportional to the applied shear stress -newtonian fluid. 
• A Fluid which obeys the Newton's Law of viscosity is termed as - newtonian fluid. 
• Static fluid- only normal stress can exist. 
•  ideal Fluids following - continuity equation. 
• The stress- strain relation of newtonian fluid is- linear. 
• An ideal flow of any fluid must fulfill the - Boundary layer theory. 
• If no resistance is encountered by displacement, such a substance is known as- Ideal fluid. 
• Fluid is a substance which offers no resistance to change of - Shape. 
• A fluid in equilibrium cannot sustain - Shear stress. 
• The volumetric change of the fluid caused by a resistance is known as- Compressibility. 
• Bulk modulus of elasticity increases with increase in - pressure. 
• Compressibility is directly proportional to Bulk Modulus. 

Basics

• Density is equal to ratio of mass and volume.
• Unit of density is kg/m3. 
• Dimension of density is M/L^3. 
• Density is inversely proportional to specific volume. 
• Density of water is maximum at 4°C. 
• Density of water is 1000kg/m3 at 4°C. 
• Specific volume is inversely proportional to mass density and equal to ratio of volume and mass. 
• Specific weight is the ratio of weight to the volume. 
• Specific weight is also known as weight density. 
• Unit of specific weight is KgN/m2. 
• Dimension of specific weight is M/L2T2. 
• Specific weight of water in SI unit is equal to 9.81 KN/m2 or 9.81*10^6 N/mm2. 
• Specific weight of sea water is more than pure water. 
• Specific weight of water is 1000 kg/m3 at atmospheric pressure, normal pressure of 760 mm Hg, at 4°C, at mean sea level. 
• Specific gravity is equal to ratio of specific weight of fluid and specific weight of water. 
• Specific gravity has a unit and dimension less.