1. 3 litre petrol weighs 2/N. Calculate (i) specific weight (ii) Density (iii) Specific volume (iv) Specific gravity
Answer:
(i) 7 × 103 N/m3
(ii) 713.6Kg/m3
(iii) 1.4 × 10-3 m3/kg
(iv) 0.7136
2. 4 m3 of a certain oil weight 31 KN. Calculate its specific weights, mass density, specific volume and specific gravity with respect to water. If the kinematic viscosity of the oil is 7.5 × 10-3 stoke, what would be its dynamic viscosity in centipoise. stoke, What would be its dynamic viscosity in centipoise.
Answer:
(i) 7.75 kN/m3
(ii) 790 kg/m3
(iii) 1.265 × 10-3 m3/kg
(iv) 0.79
(v) 0.592 centipoise
3. The pressure on the fluid filled in cylinder is increased from 8 ×105 N/m2 to 15 × 105 N/m2. Find the percentage reduction in a volume of fluid if bulk modules of elasticity is 6 ×108 N/m2
Answer:
0.1167%
4. A plate 0.05 mm distance from with a fixed plate, fluid in between moves of 1 m/s. It requires a force of 2 N/m2 to maintain the speed. Determine the viscosity.
Answer:
μ = 1 × 10-3 poise
5. The shear stress at a point in an oil is 0.35 Pa and the velocity gradient at the point is 0.28 per second. Find the viscosity of the oil of 920 kg/m3. Find the kinematic viscosity of the oil.
Answer:
(i) 1.25 Pas
(ii) 13.58 stoke
6. Find the kinematic viscosity in stokes of a liquid whose specific gravity is 0.95 and viscosity 0.011 poise.
Answer:
0.0116 stokes
7. Determine the intensity of shear of an oil having viscosity 1.2 poise and is used for lubrication in the clearance between a 10 cm diameter shaft and its journal bearing. The clearance is 1.0 mm and shaft rotates at 200 rpm.
Answer:
125.56 N/m2
8. The dynamic viscosity of an oil, used for lubrication between a shaft and sleeve is 6.5 poise. The shaft is of diameter 0.6 m and rotates at 390 rpm. Calculate the power lost in the bearing for a sleeve length of 100 mm. The thickness of the oil film is 1.5 mm.
Answer:
12.24 kw
9. Determine the diameter of (i) droplet (ii) bubble (iii) liquid jet, inside pressure is 102500 N/m2 (absolute). Assume surface tension of water as 0.073 N/m and atmospheric pressure as 101300 N/m2.
Answer:
(i) 0.24 mm
(ii) 0.48 mm
(iii) 0.12 mm
10) A steel shaft 25 mm diameter and 30 cm long falls of its own weight inside a vertical open tube 25.2 mm diameter. The clearance, assumed uniform, is filled with glycerin of viscosity 1.5 pascal. Calculate how fast will the cylinder fall at terminal conditions - take density of steel ρ = 7850Kg/m3.
Answer:
0.032 m/s
11) A plate of size 25cm and weight 1000 N sides down on inclined surface inclining 30° to the horizontal which has certain thickness of lubrication with μ = 0.1 poise. This attains velocity of 0.5 m/s over the lubricated surface. Find thickness of lubrication.
Answer:
dy = 0.625 × 10-3 mm
12) A piston having 100 mm diameter and 150 mm length moves inside a cylinder of 100.4 mm diameter. The weight of the piston is 50 N and annular space between piston and cylinder has lubrication oil of μ = 0.5 N 0.5 N-S/m2. Find the velocity with which the piston will slide inside the cylinder.
Answer:
0.424 m/s
13) The velocity distribution over a plate is given by u = 2/3 y-y2 in which the velocity is in m/sec at a distance of y m above the plate. Determine shear stress at y = 0, 0.1 and 0.2 m. Take μ = 6 poise.
Answer:
0.4, 0.028 and 0.159 N/m2
14) Determine the bulk modulus of elasticity of a fluid which is compressed in a cylinder from a volume of 0.0009 m3 at 70N/cm2 pressure to a volume of 0.0085 m3 at 270 N/cm2 pressure.
Answer:
3.6 × 103 N/cm2
15) The surface tension of water in contact with air at 20° is given as 0.0716 N/ m. The pressure inside a droplet of water is to be 0.0147 N/cm2 greater than outside pressure. Calculate the diameter of the droplet of water.
Answer:
1.94 mm
16) A 40 cm diameter pipe, converging water, branches into two pipes of diameters 30 cm and 20 cm respectively. If the average velocity in the 40 cm diameter pipe is 3 m/s, find the discharge in this pipe. Also determine the velocity in 20 cm pipe if the average velocity in 30 cm diameter pipe is 2 m/s.
Answer:
0.3769 m3 / sec, 7.5 m/s
17) A250 mm diameter pipe converging water branches into two pipes of diameter 150 mm 9 and 250 mm diameter pipe and 150 mm are 3 m/s and 2 m/s. Determine the velocity in the 100 mm diameter pipe.
Answer:
14.25 m/s
18) The diameter of a pipe change from 200 mm at a specific 5 m above datum to 50 mm at a section 3 m above datum. The pressure of water at section (1) is 500 kpa. If the velocity of flow at section (1) is 1 m/s. Find the pressure at section (2).
Answer:
V2 = 16m/s, P2 = 391.40kpa
19) At a point in the pipeline the diameter is 300 mm, the velocity of water is 3 m/ s and the pressure is 420 KN/m2 to 150 mm. Find the pressure at this point, if the pipe is (i) horizontal (ii) Vertical with flow down word (iii) vertical with flow upward.
Answer:
(i) 352.48 KN/m2
(ii) 509.44 KN/m2
(iii) 192.52 KN/ m2.
20) A horizontal verturimeter with inlet and throat diameter 300 mm and 150 mm respectively is used to measure the flow of water. The reading of differential manometer connected to the inlet and the throat is 20 cm of mercury. Find the rate of flow. Take Cd = 0.98.
Answer:
125.75 lit/sec
21. The inlet and throat diameters of a horizontal venturimeter are 300 mm respectively. The fluid flowing through the venturimeter is water. The vaccum pressure head at the throat is 370 mm of mercury. Find co-efficient of discharge. Assume that 4% of the differential head in lost between the inlet and throat. Find also the rate of flow.
Answer:
(i) Cd = 0.989
(ii) Q = 149.39 lit/sec
22) An orificemeter consisting of 150 mm of diameter orifice in a 300m diameter of pipe has co-efficient of discharge to 0.64. The pressure difference on the two sides of the orifice plate is measured by a mercury water differential manometer. If the differential gauge reading is 100 mm of mercury, find the rate of flow in litre.
Answer:
58.08 lit/sec
23) A pilot tube was inserted in a pipe to measure the velocity of water in it. If the water rises in the tube is 400 mm, find the velocity of water take Cv = 0.98.
Answer:
2.74 m/s
24) A pitot static tube is used to measure the velocity of water in the centre of pipe. The static and total pressures are 6.5 m and 8.5m respectively. Find the velocity of flow. Take Cv = 0.98.
Answer:
6.13 m/s
25) A capillary tube of 2mm bore is introduced in a fluid. The rise of fluid in the tube is found to be 10 mm. It the surface tension of the fluid is 0.076 N/m and- if the weight density is 12000 N/m3. Find the angle of contact.
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