NCEES Civil Engineering PE Exam 2

Question 1

In the Rational Method (Q = CiA) for estimating peak stormwater runoff, the variable 'i' represents:

Accepted Answer

Rainfall intensity in inches per hour for a storm duration equal to the time of concentration

Answer

In the Rational Method, 'i' is the rainfall intensity (in./hr) obtained from an IDF curve for a storm duration equal to the watershed's time of concentration.

Question 2

For a wide rectangular open channel (width much greater than depth), the hydraulic radius R is approximately equal to:

Accepted Answer

The flow depth y

Answer

For a wide rectangular channel: R = A/P = (B×y)/(B + 2y) ≈ B×y/B = y when B >> y, so R ≈ y.

Question 3

A 100-year flood event has an annual exceedance probability of:

Accepted Answer

1%

Answer

Annual exceedance probability P = 1/T = 1/100 = 0.01 = 1%, meaning any given year has a 1% chance of experiencing a flood of this magnitude or greater.

Question 4

Water hammer in a pressurized pipe system is primarily caused by:

Accepted Answer

Rapid changes in flow velocity such as sudden valve closure

Answer

Water hammer is a pressure transient caused by rapid deceleration of flow (e.g., sudden valve closure), converting kinetic energy to pressure energy and generating pressure waves that propagate through the system.

Question 5

The SCS Curve Number (CN) method is used to estimate:

Accepted Answer

Direct runoff depth in inches from a given rainfall depth

Answer

The CN method calculates direct runoff depth Q (in inches) from rainfall depth P (in inches) using Q = (P − 0.2S)² / (P + 0.8S), where S = (1000/CN) − 10.

NCEES National Council of Examiners for Engineering and Surveying Practice Practice Test

NCEES National Council of Examiners for Engineering and Surveying Practice Practice Test

NCEES Civil Engineering PE Exam 2