WorksheetsFluid and Heat Lab Final Preparation
Total questions: 50
Worksheet time: 38mins
Which of the following is a cause of pressure drop in fluid flow through pipes?
Friction on internal pipe surface
Pipe color
Water temperature only
Gravity alone
Which instrument uses a constricted throat to measure flow rate based on pressure difference?
Orifice meter
Venturimeter
Pitot tube
Globe valve
In turbulent flow, the Darcy friction factor is determined from:
Reynolds number only
Pipe diameter
Moody chart
Bernoulli equation
The head loss in a rough pipe is generally:
Zero
Less than smooth pipe
Equal to smooth pipe
Greater than smooth pipe
Given a pipe of 1 m length and 4.5 mm diameter with ΔP = 500 Pa, ρ = 1000 kg/m³, V = 2 m/s. Calculate frictional head loss.
0.051 m
0.51 m
5.1 m
51 m
Which fitting has the highest resistance coefficient (K value)?
Straight pipe
Ball valve
90° elbow
Smooth bend
Which expression correctly represents Bernoulli’s equation (in presence of friction)?
P/ρ + gz + V²/2 = constant
P/ρ + gz + V²/2 = work/mass + friction loss
V = Q/A
∆P = µQ
What is the primary purpose of using pressure taps at different points along the pipe in the Fluid Friction apparatus?
To measure flow rate directly
To determine water density
To measure head loss due to friction
To calculate pump efficiency
In the experiment, which type of pipe allows evaluation of turbulence effects due to increased surface area?
Smooth pipe
Coated pipe
Rough pipe
Plastic pipe
Why is a hydraulics bench integrated into the Fluid Friction setup?
To store experimental data
To simulate vacuum pressure
To provide controlled water flow and drainage
To detect impurities in water
How are fittings like valves and elbows tested for their resistance coefficient in this setup?
By measuring torque
By observing turbulence
By measuring pressure drop across each fitting
By changing pipe material
When plotting head loss (Δh) versus velocity (V) for laminar flow in a pipe, the graph is expected to be:
Exponential
Linear
Logarithmic
Constant
In the turbulent regime, the head loss is plotted against flow velocity. The slope of the curve indicates:
Constant resistance
Head loss is proportional to velocity squared
Direct linear relation
Reversible flow
What does a plot of friction factor (f) versus Reynolds number (Re) on a Moody chart show?
Viscosity versus pipe diameter
Smooth flow transition
Friction behavior across laminar to turbulent range
Temperature effects on head loss
A plot of pressure drop across a valve versus volumetric flow rate yields a curve that is:
Flat
Inversely proportional
Quadratic in turbulent flow regions
Always linear
If the slope of ΔP vs. Q² graph for a pipe segment increases with roughness, what does it indicate?
Decrease in flow
Better conductivity
Higher frictional losses due to surface roughness
Constant resistance
In a concentric tube heat exchanger, heat is transferred by:
Radiation only
Conduction through tube wall and convection on both sides
Direct fluid mixing
Chemical reaction
What does the overall heat transfer coefficient (U) represent?
Rate of chemical reaction
Resistance to fluid flow
Combined heat transfer through conduction and convection
Density ratio
The effectiveness (ε) of a heat exchanger is defined as:
Actual heat transfer / maximum possible heat transfer
Inlet temperature / outlet temperature
Overall U-value / area
Area × ∆T
Which flow configuration provides higher heat exchanger effectiveness?
Co-current
Counter-current
Cross flow
Parallel jets
Which parameter has the most significant effect on Reynolds number in a tube?
Fluid color
Tube length
Fluid velocity
Pressure
Given: Ti = 60°C, To = 40°C, Tc,in = 20°C, Tc,out = 35°C. Find heat transferred to cold fluid (mass flow = 1 kg/s, Cp = 4.2 kJ/kg°C)
63 kW
20 kW
15 kW
80 kW
Which of the following increases the overall heat transfer coefficient?
Lower flow velocity
Higher thermal conductivity of tube material
Scaling inside tubes
Decreasing surface area
What is the role of the control valves in both hot and cold water circuits in the heat exchanger setup?
Heating the water
Adjusting the flow rate
Measuring pressure
Preventing leakage
What feature in the apparatus allows switching between co-current and counter-current configurations?
Tube material
Color-coded pipes
A specific valve arrangement
Temperature controller
Why is the concentric tube exchanger designed with one fluid in the inner pipe and another in the annular space?
To increase visual clarity
To separate fluids while allowing thermal interaction
To simplify cleaning
To maintain pressure balance
What is the function of the immersion heater in the heat exchanger setup?
Cooling water before entering the exchanger
Preventing air bubbles
Heating the recirculating water to a setpoint temperature
Controlling flow direction
Why are multiple temperature sensors placed along both hot and cold fluid streams?
To increase experimental time
To control flow
To calculate temperature changes across the exchanger
To prevent overheating
Which graph is commonly used to evaluate the performance of a heat exchanger with changing flow rates?
Q vs. time
U vs. Reynolds number
Temperature vs. length
Pressure vs. area
A steeper temperature gradient in the co-current flow temperature profile means:
Higher effectiveness
Less heat transfer
Shorter thermal contact length
Equal outlet temperatures
What does the intersection of the hot and cold fluid temperature curves in a temperature profile graph indicate?
Boiling point
Phase change
Violation of second law
Error in data or impossible condition
When plotting effectiveness (ε) versus NTU (Number of Transfer Units), the curve for counter-current flow lies:
Below co-current
Equal to co-current
Above co-current
Exponentially decreasing
In a plot of log mean temperature difference (LMTD) vs. flow rate, LMTD typically:
Increases linearly
Remains unchanged
Decreases with higher flow rate due to less temperature change
Is independent of flow
Which equation describes constant-pressure filtration?
t/V = μαc/(2A²∆P)V + μRm/(A∆P)
Q = V/t
∆P = ρgh
R = V/t
Which parameter affects the specific cake resistance (α)?
Slurry concentration
Filter paper color
Filtrate clarity only
Ambient humidity
In filtration, cake resistance is a result of:
Fluid density
Solids deposited on filter medium
Medium temperature
Membrane pores shrinking
Which of the following is NOT a type of filtration?
Depth filtration
Surface filtration
Lateral filtration
Vacuum filtration
During vacuum filtration, increasing vacuum pressure will:
Slow down filtration
Increase resistance
Increase flow rate of filtrate
Stop filtration
Given: μ = 0.001 Pa.s, α = 1×10⁹ m/kg, c = 50 kg/m³, A = 0.01 m², ∆P = 5000 Pa, V = 0.5 L. Find t using filtration equation.
12.5 s
2.5 s
25 s
0.5 s
Which term best describes the pressure difference's effect on medium resistance in compressible cakes?
Irrelevant
Inverse square
Directly proportional
Logarithmic
What is the function of the vacuum pump in the filtration experiment?
To stir the slurry
To apply differential pressure for filtration
To dry the cake
To heat the solution
Why is calcium carbonate used in the slurry?
It's an inexpensive, insoluble solid ideal for filtration analysis
It has a strong smell for detection
It creates transparent filtrate
It reacts with the filter medium
What is the purpose of measuring time for fixed filtrate volumes?
To find flow rate
To analyze vacuum pump performance
To apply the filtration equation and determine cake resistance
To track evaporation rate
What component in the setup is used to apply and monitor vacuum pressure?
Stirring rod
Slurry tank lid
Pressure gauge
Flow controller
How is the filter medium connected to the vacuum collection system?
By metal bolts
By a rubber tube linking to a vacuumed graduated cylinder
Through a porous flask
By direct suction on slurry tank
In the filtration experiment, a plot of t/V vs. V gives a straight line. What does the slope represent?
Filtrate velocity
Cake resistance α (related)
Filter medium resistance
Cake porosity
The y-intercept in the t/V vs. V graph represents:
Filter medium resistance term
Cake porosity
Cake thickness
Solid fraction in slurry
Which graph is most useful in identifying if the cake is compressible?
Volume vs. pressure
Specific cake resistance α vs. pressure
t vs. temperature
Slurry concentration vs. filtrate clarity
A steeper slope in the t/V vs. V plot for a higher slurry concentration indicates:
Lower α
Filter clogging
Higher cake resistance α
Constant filtration rate
Why is it important to linearize the filtration data (e.g., t/V vs. V) before model fitting?
To estimate vacuum pressure
To validate filter paper material
To apply regression and extract α and Rₘ accurately
To reduce water use
