CPE II: Engineering Fundamentals and Applied Science

The CPE II Engineering Fundamentals and Applied Science domain tests whether you can apply conservation laws, mechanics, fluid/thermal/electrical principles, material behavior, and unit discipline to plant and project problems. Expect quantitative items with mixed units and assumptions that must be stated.

Core rules and concepts

• Use SI or consistent units; check dimensional homogeneity before calculating.
• Draw a free-body diagram and define sign conventions for statics and dynamics.
• Conservation of mass and energy: steady-flow energy equation includes pressure, velocity, elevation, work, and heat terms.
• Bernoulli applies to steady, incompressible, frictionless flow along a streamline; add head-loss and pump terms for real systems.
• For materials, distinguish stress from strain, elastic modulus, yield, ultimate strength, and apply a factor of safety to the governing failure mode.
• Electrical: Ohm's law and P=VI; three-phase power uses √3 V_L I_L power factor.

Worked example

A pump moves 0.020 m³/s of water (ρ=1000 kg/m³) through 25 m of head. Hydraulic power = ρgQH = 1000×9.81×0.020×25 = 4,905 W. At 72% pump efficiency, shaft power = 4,905/0.72 = 6,812 W, about 6.8 kW. Reasoning: compute useful fluid power first, then divide by efficiency; multiplying by efficiency would understate the driver requirement.

Traps that cost marks

• Using gauge and absolute pressure interchangeably in gas-law or cavitation calculations.
• Placing efficiency on the wrong side of the equation.
• Ignoring velocity-head changes when pipe diameter changes.
• Applying Bernoulli across a pump or valve without work/head-loss terms.