21. There are fourteen atoms in a unit cell of
(a) body centered cubic space lattice
(b) face centered cubic space lattice
(c) close packed hexagonal space lattice
(d) none of the above
22. An alloy of copper, tin and zinc is known as
(a) Brass (b) Bronze
(c) Gun metal (d) Babbit metal
23. Cast iron and steel pipes are produced by
(a) slush casting (b) true centrifugal casting
(c) investment casting (d) die casting
24. Electron beam welding can be carried out in
(a) pressurized inert gas chamber (b) vaccum
(c) open air (d) shielded gas environment
25. The welding process used to join ends of two pipes of uniform cross section is
(a) spot welding (b) flash butt welding
(c) upset butt welding (d) seam welding
26. For a Newtonian fluid
(a) Shear stress is proportional to shear strain
(b) Rate of shear stress is proportional to shear strain
(c) Shear stress is proportional to rate of shear strain
(d) Rate of shear stress is proportional to rate of shear strain
27. Oil in a hydraulic cylinder is compressed from an initial volume 2 m3 to 1.96 m3 and
the pressure increase is from 40 MPa to 80 MPa. The bulk modulus of elasticity
of oil is
(a) 1000 MPa (b) 2000 MPa
(c) 4000 MPa (d) 8000 Mpa
28. Pitot tube is used for measurement of
(a) pressure difference (b) discharge through pipe
(c) velocity of flow at required point (d) viscosity of flowing liquid
29. For laminar flow through a long pipe, the pressure drop per unit length is
(a) In direct proportion to the cross sectional area
(b) In proportion to diameter of pipe
(c) In inverse proportion to the square of cross sectional area
(d) In inverse proportion to cross sectional area
30.Oil flows through 200 mm diameter horizontal cast iron pipe with friction factor of 0.0225 of length 500 mtr. The volumetric flow rate is 0.2 m3/sec. The head loss in mtr. due to friction will be
(a) 232.36 (b) 0.116
(c) 116.18 (d) 18.22
31. A hydraulic turbine develops 1000 kW power for a head of 40 m. If the head is reduced
to 20 m, power developed in kW is
(a) 177 (b) 354
(c) 500 (d) 607
32. Impulse turbine is used for
(a) low head of water (b) high head of water
(c) medium head of water (d) high discharge
33. Laminar flow occurs in pipes, when Reynolds number is
(a) Lies between 2000-3000 (b) Lies between 3000-4000
(c) Less than 2000 (d) Less than 1000
34. Power in kW required to drive Centrifugal pump with discharge of Q m3/sec, Head in
H mtr, specific weight of fluid as w N/m3 and overall efficiency of pump as I shall be
(a) w H/Qη (b) w QH/η
(c) w Q/Hη (d) w Qη /H
35. If the net positive section head(NPSH) for the pump is not satisfied, then
(a) no flow take place (b) efficiency will be low
(c) cavitation will be formed (d) pump will not start
36. For a given heat flow and for the same thickness, the temperature drop across material will be maximum for
(a) Copper (b) Steel
(c) Glass wool (d) Brick
37. The rate of heat flow through a body is $Q = \frac{kA(T_1-T_2)}{x}$, the term x/kA is known as
(a) thermal coefficient (b) thermal resistance
(c) thermal conductivity (d) thermal gradient
38. A furnace made of a red brick wall of thickness 0.5 mtr. and conductivity 0.7 W/mK is replaced by alternate material of conductivity 0.14 W/mK. For the same heat loss and temperature drop, required thickness of alternate material will be
(a) 0.2 mtr. (b) 0.1 mtr.
(c) 0.3 mtr. (d) 0.4 mtr.
39. The concept of overall coefficient of heat transfer is used in calculating heat transfer by
(a) conduction
(b) convection
(c) conduction and radiation
(d) conduction and convection
40. With an increase in the thickness of insulation around a circular pipe, heat loss to surroundings due to
(a) Convection and conduction increases
(b) Convection and conduction decreases
(c) Convection increases while due to conduction decreases
(d) Convection decreases while due to conduction increases
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