Multiple Choice Practice Questions
1- An ideal fluid flows through a long horizontal circular pipe. In one
region of the pipe, it has radius R. The pipe then widens to radius 3R.
What is the ratio of the fluids speed in the region of radius R to the
speed of the fluid in region with radius 2R?
A) ¼
B) ½
C) 1
D) 2
E) 4
2- A fluid is force through a pipe of changing cross section as shown. In
which section would the pressure of the fluid be a minimum?
A) I
B) II
C) III
D) IV
E) all section have the same pressure
3- A liquid has a specific gravity of 0.357. What is its density?
a) 357 kg/m3
b) 643 kg/m3
c) 1000 kg/m3
d) 3570 kg/m3
4- Water flows through a pipe. The diameter of the pipe at point B is
larger than at point A. Where is the water pressure greater?
a) Point A
b) Point B
c) Same at both A and B
d) Cannot be determined from the information given.
5- Liquid flows through a 4 cm diameter pipe at 1.0 m/s. There is a 2 cm
diameter restriction in the line. What is the velocity in this restriction?
a) 0.25 m/s
b) 0.50 m/s
c) 2 m/s
d) 4 m/s
6- The units of heat flux are?
a) watts
b) Joules
c) Joules/maters2
d) watts/maters2
e) Joules/kg K
7- The units of thermal conductivity are?
a) watts/maters2 K
b) Joules
c) Joules/maters2
d) Joules/second maters K
e) Joules/kg K
8- The heat transfer coefficient is defined by the relationship?
a) h = m Cp ΔT
b) h = k / L
c) h = q / ΔT
d) h = Nu k / L
e) h = Q/ ΔT
9- Which of these materials has the highest thermal conductivity?
a) Air
b) Water
c) Mid steel
d) Titanium
e) Aluminum
10- Which of these materials has the lowest thermal conductivity?
a) Air
b) Water
c) Mid steel
d) Titanium
e) Aluminum
11- what is the heat flow through a brick wall of area 10 m2, thickness 0.2
m, k=0.1 W/m.K with surface temperature on one side of 200C and
100C on the other?
a) 50 watts
b) 50 Joules
c) 50 watts/m2
d) 200 watts
e) 200 watts/m2
12- A pipe of surface are 2m2 m has a surface temperature of 1000C, the
adjacent fluid is at 200C the heat coefficient acting between the two is
20 W / m2 K. what is the heat flow by convection?
a) 1600 W
b) 3200 W
c) 20 W
d) 40 W
e) Zero
13- The different modes of heat transfer are?
a) Forced convection, free convection and mixed convection
b) Conduction, radiation and convection
c) Laminar and turbulent
d) Evaporation, condensation and boiling
e) Cryogenic, ambient and high temperature
14- The different modes of flow rate are?
a) Forced convection and free convection and mixed convection
b) Conduction, radiation and convection
c) Laminar and turbulent
d) Heat and mass transfer
e) Cryogenic, ambient and high temperature
15- The thermal diffusivity, α, is defined as?
a) α = μ Cp / k
b) α = k Cp / ρ
c) α = k/ ρ Cp
d) α = h L / k
e) α = L/ k
16- the Poisson's ratio, υ is defined as?
a) υ = ɛL/ ɛT
b) υ = σ/ ɛ
c) υ = ɛT / ɛL
d) υ = ɛ/ E
e) υ = E ɛ
17- The ultimate strength is ………. yield stress?
a) Greater than
b) lower than
c) equal
d) Cannot be determined from the information given.
18- The natural frequencies for the discrete system are?
a) infinite
b) Finite and equal the degree of freedom
c) Finite and not equal the degree of freedom
d) all.
19- Classification of flow (turbulent or laminar flow) by the ……….. ?
a) Mach Number
b) Reynolds Number
c) Nusselt Number
d) Newton second law.
e) Prandtl Number
20- The compression ratio in the diesel engine is………..compression
ratio in the benzene engine?
a) Lower than
b) Greater than
c) equal
d) Cannot be determined from the information given.
21- The barometer is used to measure the?
a) Heat transfer
b) Mass transfer
c) Temperature
d) Pressure
22- A large value of heat coefficient is equivalent to?
a) A large thermal resistance
b) A small thermal resistance
c) Infinite thermal resistance
d) Zero thermal resistance
e) It depends on the fluid temperature
23- The unit of thermal diffusivity, α, is?
a) α = kg/ m.s
b) α = m2/ s
c) α = m/ s2
d) α = kg/ m2 .s
e) α = m.s
24- Thermocouple is used to measure?
a) Heat transfer
b) Mass transfer
c) Temperature
d) Pressure