BCE Bachelor of Civil Engineering 3 — Questions and Answers
Question 1: In reinforced concrete design (ACI 318), the minimum concrete cover for reinforcement in a slab exposed to weather is typically:
- 3/4 inch
- 1.5 inches (Correct answer)
- 2 inches
- 3 inches
Correct answer: 1.5 inches
ACI 318 requires 1.5 inches of cover for slabs, walls, and joists not exposed to weather when bar size is #5 or smaller.
Question 2: Which hydrograph method estimates the runoff response of a watershed to a unit rainfall excess?
- Rational method
- Unit hydrograph method (Correct answer)
- Manning's equation
- Green-Ampt infiltration model
Correct answer: Unit hydrograph method
The unit hydrograph represents the direct runoff hydrograph resulting from one inch of rainfall excess uniformly distributed over the watershed.
Question 3: Mohr's circle is used in structural and geotechnical engineering to graphically determine:
- Beam deflection under load
- Principal stresses and shear stresses at a point (Correct answer)
- Settlement of a foundation
- Moment distribution in frames
Correct answer: Principal stresses and shear stresses at a point
Mohr's circle graphically represents the state of stress at a point, allowing determination of principal stresses and maximum shear stress.
Question 4: A retaining wall that relies on its own weight to resist overturning is called a:
- Cantilever retaining wall
- Gravity retaining wall (Correct answer)
- Sheet pile wall
- Anchored wall
Correct answer: Gravity retaining wall
Gravity retaining walls use their large self-weight (mass) to resist the lateral earth pressure without relying on reinforcement.
Question 5: In open channel hydraulics, critical flow occurs when the Froude number equals:
- 0
- 0.5
- 1.0 (Correct answer)
- 2.0
Correct answer: 1.0
At critical flow, Fr = 1, indicating the flow transitions between subcritical (Fr < 1) and supercritical (Fr > 1) regimes.
Question 6: The 'slump test' for fresh concrete primarily measures:
- Compressive strength
- Water-cement ratio
- Workability (consistency) (Correct answer)
- Aggregate size
Correct answer: Workability (consistency)
The slump test measures the consistency or workability of fresh concrete by recording how much a cone-shaped sample slumps.
Question 7: Which type of surveying method uses the angles and distances from a single control point to locate features?
- Traverse surveying
- Radiation (polar) method (Correct answer)
- Triangulation
- Leveling
Correct answer: Radiation (polar) method
The radiation method sets up an instrument at one station and locates surrounding points by measuring angles and distances from that point.
BCE Bachelor of Civil Engineering 3
In reinforced concrete design (ACI 318), the minimum concrete cover for reinforcement in a slab exposed to weather is typically: