Title Mechanical Propeerties of Fluids.pdf ✅

8. A boy can reduce the pressure in his lungs to 750 mm of mercury. Using a straw he can drink water from a glass upto the maximum depth of (atmospheric pressure = 760 mm of mercury; density of mercury = 13.6gcm−3 ) NCERT Page-253/N-182, 183 (a) 13.6 cm (b) 9.8 cm (c) 10 cm (d) 76 cm 9. What is the absolute pressure of the gas above the liquid surface in the tank shown in fig. Density of oil = 820 kg/m3 , density of mercury = 13.6 × 103 kg/m3 . Given 1 atmospheric pressure = 1.01 × 105 N/m2 . (a) 3.81 × 105 N/m2 (b) 6 × 106 N/m2 NCERT Page-254 /N − 182, 183 (c) 5 × 107 N/m2 (d) 4.6 × 102 N/m2 10. Figure shows a U-tube of uniform cross-sectional area A, accelerated with acceleration a as shown. If d is the separation between the limbs, then what is the difference in the levels of the liquid in the U-tube is (a) ad g (b) ag d (c) a d (d) dg a NCERT Page-254/N-182, 183 11. Hydraulic lifts and hydraulic brakes are based on NCERT Page-255 / N-185 (a) Archimedes' principle (b) Bernoulli's principle (c) Stoke's law (d) Pascal's law 12. Pressure applied to enclosed fluid is NCERT Page-252 / N-182 (a) increased and applied to every part of the fluid. (b) diminished and transmitted to wall of container. (c) increased in proportion to the mass of the fluid and then transmitted (d) transmitted unchanged to every portion of the fluid and wall of containing vessel. 13. In a hydraulic lift, compressed air exerts a force F1 on a small piston having a radius of 5 cm. This pressure is transmitted to a second piston of radius 15 cm. If the mass of the load to be lifted is 1350 kg, find the value of F1 ? The pressure necessary to accomplish this task is NCERT Page-256 / N-185 (a) 1.4 × 105 Pa (b) 2 × 105 Pa (c) 1.9 × 105 Pa (d) 1.9 Pa
14. A pressure-pump has a horizontal tube of cross sectional area 10 cm2 for the outflow of water at a speed of 20 m/s. The force exerted on the vertical wall just in front of the tube which stops water horizontally flowing out of the tube, is: NCERT Page-256 [given: density of water = 1000 kg/m3 ] (a) 300 N (b) 500 N (c) 250 N (d) 400 N 15. Two cylindrical vessels of equal cross-sectional area 16 cm2 contain water upto heights 100 cm and 150 cm respectively. The vessels are interconnected so that the water levels in them become equal. The work done by the force of gravity during the process, is [Take density of water = 103 kg/m3 and g = 10 ms−2 ] NCERT Page-254 (a) 0.25 J (b) 1 J (c) 8 J (d) 12 J 9.3 STREAMLINE FLOW 16. Beyond the critical speed, the flow of fluids becomes NCERT Page-257/N-186 (a) streamline (b) turbulent (c) steady (d) very slow 17. Streamline flow is more likely for liquids with NCERT Page-257/N-186 (a) high density and low viscosity (b) low density and high viscosity (c) high density and high viscosity (d) low density and low viscosity 18. For flow of a fluid to be turbulent NCERT Page-257, 264/N-186 (a) fluid should have high density (b) velocity should be large (c) reynold number should be less than 2000 (d) both (a) and (b) 19. In which flow the velocity of fluid particles reaching a particular point is same at all time? (a) vigrous flow NCERT Page-257/ N-186 (b) steady flow (c) turbulant flow (d) None of these 20. Figure shows a liquid flowing through a tube at the rate of 0.1 m3 /s. The tube is branched into two semicircular tubes of cross-sectional area A/3 and 2A/3. The velocity of liquid at Q is (the cross-section of the main tube is A = 10−2 m2 and vP = 20 m/s ) NCERT Page-257 / N-187 (a) 5 m/s (b) 30 m/s (c) 35 m/s (d) None of these
21. Oil is filled in a cylindrical container upto height 4 m. A small hole of area ' p ' is punched in the wall of the container at a height 1.52 m from the bottom. The crosssectional area of the container is Q. If p q = 0.1 then v is (where v is the velocity of oil coming out of the hole) NCERT Page-257/ N-187 (a) 5√2 (b) 6√3 (c) 8√2 (d) 7√5 22. In the figure, the velocity V3 will be NCERT Page-257 / N-187 (a) Zero (b) 4 ms−1 (c) 1 ms−1 (d) 3 ms−1 9.4 BERNOULLIS PRINCIPLE 23. In Bernoulli's theorem which of the following is conserved? NCERT Page-259 / N-187 (a) Mass (b) Linear momentum (c) Energy (d) Angular momentum 24. A liquid is allowed to flow into a tube of truncated cone shape. Identify the correct statement from the following: NCERT Page-257 / N-187 (a) the speed is high at the wider end and high at the narrow end. (b) the speed is low at the wider end and high at the narrow end. (c) the speed is same at both ends in a stream line flow. (d) the liquid flows with uniform velocity in the tube. 25. Water flows through a frictionless tube with a varying cross-section as shown in fig. Pressure P at points along the axis is represented by NCERT Page-259/N-188 (a) (b) (c) (d)