NCEES Mechanical Engineering PE Exam

Question 1

On the NCEES PE Mechanical exam, which thermodynamic cycle best describes the operation of a steam power plant?

Accepted Answer

Rankine cycle

Answer

Brayton cycle

Answer

Otto cycle

Answer

Carnot cycle

Question 2

In the NCEES PE Mechanical exam, what does the 'coefficient of performance (COP)' of a refrigeration cycle represent?

Accepted Answer

The ratio of useful refrigeration effect to work input

Answer

The ratio of heat rejected to work input

Answer

The thermal efficiency of the compressor

Answer

The ratio of condenser heat to evaporator heat

Question 3

For the NCEES PE Mechanical exam, which equation defines the steady-flow energy equation (SFEE) for an open system?

Accepted Answer

Q̇ - Ẇ = ṁ[(h2 - h1) + (V2² - V1²)/2 + g(z2 - z1)]

Answer

Q - W = ΔU

Answer

PV = nRT

Answer

W = ∫P dV

Question 4

On the NCEES PE Mechanical exam, what is the significance of the 'isentropic efficiency' of a turbine?

Accepted Answer

It is the ratio of actual work output to ideal isentropic work output

Answer

It is the ratio of heat input to mechanical work

Answer

It measures heat loss through the turbine casing

Answer

It is the ratio of inlet to outlet pressure

Question 5

In the NCEES PE Mechanical exam, which law states that the total pressure of a gas mixture equals the sum of partial pressures of its components?

Accepted Answer

Dalton's law of partial pressures

Answer

Fourier's law

Answer

Fick's law of diffusion

Answer

Newton's law of cooling

Question 6

For the NCEES PE Mechanical exam, which dimensionless number characterizes the ratio of inertial forces to viscous forces in fluid flow?

Accepted Answer

Reynolds number

Answer

Prandtl number

Answer

Nusselt number

Answer

Mach number