NCEES Mechanical Engineering

Question 1

On the NCEES PE Mechanical exam, the first law of thermodynamics for a closed system states that:

Accepted Answer

Change in internal energy equals heat added minus work done by the system

Answer

The first law states ΔU = Q – W: the change in internal energy equals heat added to the system minus work done by the system.

Question 2

In NCEES PE Mechanical problems, the Carnot efficiency of a heat engine operating between TH = 600 K and TL = 300 K is:

Accepted Answer

50%

Answer

Carnot efficiency = 1 − TL/TH = 1 − 300/600 = 0.50 = 50%.

Question 3

Which dimensionless number is used to characterize the ratio of inertial forces to viscous forces in fluid flow, as assessed on the NCEES PE Mechanical exam?

Accepted Answer

Reynolds number

Answer

The Reynolds number Re = ρVD/μ represents the ratio of inertial to viscous forces and determines laminar vs. turbulent flow.

Question 4

For the NCEES PE Mechanical exam, Bernoulli's equation is valid when flow is:

Accepted Answer

Incompressible, inviscid, and steady along a streamline

Answer

Bernoulli's equation applies to steady, incompressible, inviscid flow along a streamline.

Question 5

In NCEES Mechanical Engineering fundamentals, the stress-strain curve's elastic region is characterized by:

Accepted Answer

A linear relationship described by Hooke's Law (σ = Eε)

Answer

In the elastic region, stress is proportional to strain via Hooke's Law: σ = Eε, and deformation is fully recoverable.

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 Mechanical Engineering