Engineering Quiz
Questions: 16 · 10 minutes
1. A centrifugal pump begins making a crackling noise, and inspection suggests vapor bubbles are forming and collapsing near the impeller. What is the most likely cause?
The impeller has eliminated all pressure variation
Discharge pressure has made the liquid incompressible
Local liquid pressure has fallen below the liquid's vapor pressure
The liquid temperature has fallen below its freezing point
2. A steel rod and an aluminum rod have the same length and cross-sectional area and carry the same axial tensile load. Both remain elastic. Since aluminum has the lower Young's modulus, how do their extensions compare?
The steel rod extends more
Neither rod extends under a constant load
They extend by the same amount
The aluminum rod extends more
3. A rotating shaft experiences repeated stress cycles whose peak stress is below the material's yield strength. After many cycles, a crack develops and grows. Which phenomenon best explains the failure?
Elastic recovery
Steady-state creep
Fatigue
Galvanic insulation
4. Ideal incompressible flow moves through a horizontal pipe that narrows. Neglecting losses, what happens in the narrower section?
Velocity and static pressure both increase
Velocity and static pressure both decrease
Velocity decreases while static pressure increases
Velocity increases while static pressure decreases
5. A simply supported beam carries a single downward point load P at its midpoint. Ignoring the beam's own weight, what are the vertical reactions at the two supports?
P at each support
Zero at both supports because the load is centered
P/2 upward at one support and P/2 downward at the other
P/2 upward at each support
6. A 20-tooth driving gear rotates at 300 rpm and meshes externally with a 60-tooth driven gear. What is the driven gear's speed and direction?
900 rpm in the same direction
900 rpm in the opposite direction
100 rpm in the same direction
100 rpm in the opposite direction
7. A 6 Ω resistor and a 3 Ω resistor are connected in parallel. What is their equivalent resistance?
9 Ω
4.5 Ω
2 Ω
0.5 Ω
8. A hole may measure from 20.00 to 20.05 mm, while its mating shaft may measure from 19.98 to 20.02 mm. How should this fit be classified?
A transition fit, because either clearance or interference is possible
Always an interference fit, with at least 0.02 mm interference
A line fit with zero clearance in every assembly
Always a clearance fit, with at least 0.02 mm clearance
9. A sensor gives nearly identical readings each time, but every reading is about 5 units above a trusted reference. Which description best fits the sensor's performance?
Accurate but imprecise
Precise but inaccurate
Both accurate and precise
Neither measurable nor repeatable
10. In a beam under ordinary bending, where is the magnitude of bending stress generally greatest?
At the neutral axis
At the outermost fibers, farthest from the neutral axis
Uniformly throughout the cross-section
Only at the centroid, regardless of loading
11. On a typical tensile stress-strain curve for a ductile metal, what does reaching the yield region indicate?
The specimen has necessarily fractured
Appreciable permanent deformation can begin
Stress has become zero while strain continues rising
The material's density has suddenly doubled
12. A component is expected to fail at a load of 12 kN. Using a factor of safety of 3 against that failure mode, what working load does the simple allowable-load approach give?
3 kN
9 kN
4 kN
36 kN
13. A closed system receives 500 J of heat and does 200 J of work on its surroundings. Neglecting changes in kinetic and potential energy, what is the change in internal energy?
An increase of 300 J
A decrease of 300 J
An increase of 700 J
A decrease of 700 J
14. A negative-feedback controller regulates room temperature with an electric heater. The measured temperature rises above the setpoint. What response is consistent with negative feedback?
Reduce heater power to oppose the temperature rise
Hold heater power constant regardless of the error
Increase heater power to amplify the temperature error
Reverse the temperature sensor's displayed units
15. Two uniform insulation layers cover the same wall area, with one layer directly outside the other. Assuming one-dimensional steady conduction, how is the total thermal resistance found?
Add the layers' conduction resistances because they are in series
Multiply the two resistances, regardless of their units
Use only the layer with the higher thermal conductivity
Subtract the thinner layer's resistance from the thicker layer's resistance
16. Which expression in SI base units is dimensionally equivalent to one joule?
Kilogram metre per second
Kilogram metre squared per second squared
Kilogram per metre-second squared
Kilogram metre squared per second