Study Set Content:
261. What is the absolute pressure exerted on the surface of a submarine cruising 300 ft below
the free surface of the sea? Assume specific gravity of sea water is 1.03.
A. 133.9 psia B. 148.6 psia
C. 100.7 psia D. 103.7 psia
B. 148.6 psia
263. What is the work required to accelerate an 800-kg car from rest to 100 km/h on a level
road?
A. 308.6 kJ B. 806.3 kJ C. 608.3 kJ D. 386 kJ
A. 308.6 kJ
264. Assuming that there are no heat effects and no friction effects, find the speed of a 3220-
lbm body after it falls 778 ft from rest.
A. 422 ft/s B. 424 ft/s C. 224 ft/s D. 424 ft/s
C. 224 ft/s
5. What is the flow rate through a pipe 4 inches in diameter carrying water at a velocity of 11
ft/s?
A. 430.84 gpm B. 7.18 gpm
C. 340.28 gpm D. 39.16 gpm
A. 430.84 gpm
266. If the specific weight of a liquid is 58.5 lbf per cubic foot, what is the specific volume of the
liquid in cm3
/g?
A. 0.5321 cm3
/g B. 0.6748 cm3
/g C. 0.9504 cm3
/g D. 1.0675 cm3
/g
D. 1.0675 cm3
/g
267. What is the resulting pressure when one pound of air at 0.3 psig and 200°F is heated at
constant volume to 800°F?
A. 0.572 psig B. 28.6 psia
C. 7.857 psia D. 1.2 psig
B. 28.6 psia
268. A small pump serving as model, when tested in laboratory using water at 3600 rpm,
delivered 30 cfs at a head of 125 ft. If the efficiency of this model pump is 84%, predict thehorsepower input to the prototype pump if it is to develop the same head as model pump and
the model pump has a scale ratio of 1:10. Assume the efficiency of the prototype pump is 90%.
A. 50.6 hp B. 4730 hp C. 3740 hp D. 60.5 hp
B. 4730
269. Pump at is best efficiency point (BEP) has a capacity of 10,500 gpm while developing a
head of 60 ft at a rotative speed of 1450 rpm. What is the specific speed of the pump?
A. 2760 B. 1450 C. 2476 D. 6892
D. 6892
270. A pump will be installed below the reservoir water surface with a required net positive
suction head (NPSHR) of 50 ft. The barometric pressure is 14.3 psia, and the vapor pressure is
0.5 psia. Assume friction losses in the intake piping are 5 ft. Find the maximum allowable
elevation of the pump relative to the water surface intake to avoid cavitation.
A. 45 ft B. 55 ft C. 18.2 ft D. 23.2 ft
D. 23.2 ft
271. A centrifugal pump is at best efficiency point (BEP). Assume the pump characteristic are
head, h = 7 m, flow rate, Q = 19 liters/s, and rotative speed n = 1170 rpm. Find the specific
speed in SI units.
A. 0.4 B. 0.71 C. 10.41 D. 3.94
B. 0.71
272. The pressure of a confined gas at a constant temperature is tripled, what will happen to
the volume?
A. The volume will be tripled
B. The volume will be reduced to one-third of its original value
C. The volume will remain unchanged
D. The volume is constant
B. The volume will be reduced to one-third of its original value
273. A 15 in. diameter fan operates at 1600 rpm and develops a head of 6 in. of water and
delivers 120 cfm. What volumetric capacity for geometrically similar fan will develop 6 in of
water at 1300 rpm?
A. 147.7 cfm B. 181.8 cfm
C. 97.5 cfm D. 79.2cfm
. 181.8 cfm
274. A radial-flow pump operating at maximum efficiency at a specific speed of 2500 is to
deliver 260 gpm against a head of 129 ft at a rotative speed of 2100 rpm. Find the required
number of stages (i.e., impellers).
A. 2 stages B. 3 stages
C. 4 stages D. 5 stages
C. 4 stages
275. How many identical turbines, operating at 139.0 rpm and 91% efficiency (specific speed =
5.4), are needed to exploit a head of 1200 ft and a flow of 1660 ft3
/s?
A. 2 turbines B. 3 turbines
C. 4 turbines D. 5 turbines
B. 3 turbines
276. How many poles should a 60-Hz generator have, if it is connected to a turbine operating
under a design head of 3000 ft with a flow of 82 cfs? Assume turbine specific speed and
efficiency 3 and 84 percent respectively.
A.10-pole B. 12-pole C. 14-pole D. 16-pole
D. 16-pole
278. What type of turbine delivers 25,000 bhp at 500 rpm under a net head of 5350 ft?
A. Impulse turbine B. Francis turbine
C. Kaplan turbine D. Propeller turbine
A. Impulse turbine
279. A 26-hp pump delivers 475 gpm of gasoline (γ = 42.5 lb/ ft3
) at 20 C with 78% efficiency.
What pressure rise result across the pump?
A. 30.2 psi B. 32.7 psi
C. 120.3 psi D. 73.2 psi
. 73.2 psi
280. A model pump delivering water at 180°F (γ = 60.6 lb/ ft3
; pvapor = 7.54 psia) at 900 gpm and
2500 rpm begins to cavitate when the inlet pressure and velocity are 13 psia and 22 fps. Find
the required NPSH of a prototype which is 4 times larger and runs at 1100 rpm.
A. 63.5 ft B. 20.49 ft C. 6.61 ft D. 36 ft
A. 63.5 ft
281. The diameter of the discharge pipe is 8 in. and that of the intake pipe is 10 in. The pressure
gage at discharge reads 32 psi, and vacuum gage at the intake reads 12 in. Hg. If the discharge
flow rate = 4.0 ft3
/s of water and the brake horsepower is 49.0, find the efficiency. The intake
and the discharge are at the same elevation.
A. 82.2% B. 80.9% C. 55.8% D. 58.46%
. 82.2%
282. A piston positive-displacement pump (PDP) has a 6-in diameter and a 2.5-in stroke. Its
crankshaft rotates at 300 rpm. Calculate its output at 94 percent volumetric efficiency.
A. 12.27 cfm B. 13.5 cfm
C. 10 cfm D. 11.53 cfm
. 11.53 cfm
