Mixed Deck — All EIT Topics Flashcards

On a Mohr's circle, the radius represents:

Answer: The maximum in-plane shear stress

The radius of Mohr's circle equals the maximum in-plane shear stress τ_max = (σ₁ − σ₂)/2.

Which data structure operates on a Last-In-First-Out (LIFO) principle?

Answer: Stack

A stack follows LIFO order—the most recently inserted element is the first to be removed.

What is Ohm’s Law?

Answer: V = IR

Ohm's Law describes the fundamental relationship between voltage (V), current (I), and resistance (R) in an electrical circuit. It states that the voltage across a conductor is directly proportional to the current flowing through it, provided temperature and other physical conditions remain constant. The mathematical expression for this relationship is V = IR.

For a hollow circular shaft in torsion, which parameter most directly increases torsional stiffness?

Answer: Increasing polar moment of inertia J

Torsional stiffness = GJ/L; increasing the polar moment of inertia J directly increases stiffness.

A perpetuity pays $500 per year forever. If the interest rate is 8%, what is the present value?

Answer: $6,250

PV of a perpetuity = A/i = 500/0.08 = $6,250.

The specific speed of a pump is used to:

Answer: Classify pump type and predict performance at varying scales

Specific speed N_s = N√Q / H^(3/4) classifies pumps (centrifugal, mixed, axial) and guides selection and scaling.

According to the NSPE Code of Ethics, engineers shall continue their professional development throughout their careers. Which of the following is an example of fulfilling this obligation?

Answer: Attending technical seminars and workshops.

The NSPE Code of Ethics explicitly states that engineers should keep current in their specialty fields by engaging in professional practice, participating in continuing education courses, reading technical literature, and attending professional meetings and seminars. While mentoring, license renewal, and varied work experience are all valuable professional activities, attending seminars and workshops directly addresses the requirement for continuing education and staying current with technical advancements.

A machine costs $50,000 and has a salvage value of $5,000 after 10 years. Using straight-line depreciation, what is the annual depreciation?

Answer: $4,500

Annual depreciation = (Cost − Salvage)/Life = (50,000 − 5,000)/10 = $4,500.

If f(x) = x³ - 6x² + 9x, at which x-value does a local minimum occur?

Answer: x = 3

f'(x) = 3x² - 12x + 9 = 0 gives x = 1 (local max) and x = 3 (local min), verified by the second derivative test.

What is the value of the derivative of x^2 at x = 3?

Answer: 6

To find the value of the derivative of x^2 at x = 3, first, we apply the power rule for differentiation, which states that the derivative of x^n is nx^(n-1). For x^2, the derivative is 2x^(2-1) = 2x. Next, we substitute x = 3 into the derivative, yielding 2 * 3 = 6.

The Henderson-Hasselbalch equation is primarily used to calculate:

Answer: pH of a buffer solution

pH = pKa + log([A⁻]/[HA]) is the Henderson-Hasselbalch equation for buffer pH.

An isolated system undergoes an irreversible process. What can be said about its entropy?

Answer: Entropy increases

For an isolated system (δQ = 0), the second law requires dS ≥ 0, with entropy increasing for irreversible processes.

A project has an initial cost of $80,000, annual benefits of $20,000, and a life of 6 years. At i = 10%, what is the benefit-cost ratio?

Answer: 1.09

PV of benefits = 20,000·(P/A,10%,6) = 20,000·4.355 = $87,100; B/C = 87,100/80,000 ≈ 1.09.

An engineer is asked to provide an expert opinion in a legal case outside their area of expertise. The ethical course of action is to:

Answer: Decline and refer the attorney to a qualified expert

Engineers should only express professional opinions in areas where they are competent, and should decline engagements outside their expertise.

For fully developed laminar flow in a circular pipe, the friction factor f is related to Reynolds number Re by:

Answer: f = 64/Re

The Hagen-Poiseuille result gives the Darcy friction factor f = 64/Re for laminar pipe flow.

In a free vibration test, successive amplitudes are 5 mm and 2.5 mm. What is the logarithmic decrement?

Answer: 0.693

δ = ln(x₁/x₂) = ln(5/2.5) = ln(2) ≈ 0.693.

During a constant-volume (isochoric) heating process of an ideal gas, which of the following is true?

Answer: All heat added goes to increasing internal energy

At constant volume W = 0, so by the first law Q = ΔU; all heat increases internal energy.

In the method of joints, when only two non-collinear members meet at an unloaded joint, what can be concluded?

Answer: Both members are zero-force members

At an unloaded joint where only two non-collinear members meet, both must be zero-force members to satisfy ΣFx = 0 and ΣFy = 0.

What is the present value of $5,000 received at the end of each year for 8 years at 6% interest?

Answer: $31,047

PV = 5,000·(P/A,6%,8) = 5,000·6.210 = $31,050 ≈ $31,047.

Which material is most likely to follow Hooke's Law?

Answer: Steel

Hooke's Law describes the linear elastic behavior of materials, stating that stress is directly proportional to strain within the elastic limit. Steel is an excellent example of a material that exhibits a clear and predictable linear elastic region under typical engineering loads, making it suitable for applications where Hooke's Law is applied. Materials like rubber, plastic, and lead often have more complex, non-linear elastic responses or lower elastic limits.