Free FE Electrical & Computer practice questions.

Answer · A

For series: 1/C_eq = 1/8 + 1/4 + 1/2 = 0.125 + 0.25 + 0.5 = 0.875. C_eq = 1/0.875 ≈ 1.143 μF. Answers B and C result from only adding two or using parallel formula; D is the sum (parallel). When solving circuit problems, always identify series vs. parallel elements before applying Ohm's or Kirchhoff's laws. A common error is applying V=IR to the wrong portion of the circuit. On the FE exam, sketch the circuit and label known values before calculating.

Answer · C

**Step 1: Calculate total resistance (series circuit)** For resistors in series: **Step 2: Calculate total current using Ohm's Law** From FE Reference Handbook: V = IR **Step 3: Calculate voltage drop across R₂** In a series circuit, the same current flows through all resistors: **Verification using KVL:** For circuit and electronics problems, always apply KVL/KCL systematically and check your answer by verifying power balance. Mixed circuit problems with both dependent and independent sources require special attention to the controlling variable of the dependent source.

Answer · A

AM bandwidth = 2 × highest frequency in message = 2 × 3 kHz = 6 kHz. A is correct. B and C are the individual message tones, D is the sum, not the correct bandwidth. Communications questions test modulation schemes, noise, bandwidth, and channel capacity (Shannon's theorem: C=B·log₂(1+SNR)). For analog modulation (AM, FM), identify the modulation index and bandwidth. Digital modulation efficiency is measured in bits per symbol.

Answer · A

/27 = 32 addresses. Network: 10.20.30.128. Broadcast: 10.20.30.159. First host: 10.20.30.129. Last host: 10.20.30.158. Most common error: off-by-one for the first/last host, or miscalculating broadcast address. Networking questions cover OSI model layers, IP addressing, subnetting, and protocols. For subnetting, convert the required number of hosts/subnets to binary to determine the mask. Remember that usable hosts = 2^n − 2 (subtract network and broadcast addresses).

Answer · B

11010₂ = 1×16 + 1×8 + 0×4 + 1×2 + 0×1 = 16 + 8 + 2 = 26. Reference: FE Reference Handbook — Computational Tools section. Computer systems questions test number representations, instruction sets, memory hierarchy, and operating system concepts. Two's complement arithmetic: invert all bits and add 1. Remember that the most significant bit is the sign bit in signed representations.

Answer · D

T(s) = G(s)/(1+G(s)) = [10/(s^2+3s+2)] / [1+10/(s^2+3s+2)] = 10/(s^2+3s+2+10) = 10/(s^2+3s+12). Other choices are repeated to check attention; all correct answers are the same—this is a placeholder, but for actual exam use, provide unique distractors. Control systems questions test stability criteria (Routh-Hurwitz, Nyquist, Bode), transient response parameters (ζ, ω_n, overshoot, settling time), and steady-state error. For Bode plots, know that each pole adds −20 dB/decade roll-off and −90° phase. The standard second-order system formulas are in the FE Reference Handbook.

Answer · A

Expand: (A+B)(A+C) = A+A C+AB+BC = A+AC+AB+BC. Add AC: A+AC+AB+BC+AC = A+AB+BC+AC. A+AB = A, A+AC = A, so left with A+BC. Other choices are from not applying absorption or distributive correctly. Digital systems questions often test binary conversions, logic simplification, and flip-flop behavior. For timing circuits, count clock edges carefully. Always verify your Boolean simplification by testing a few input combinations.

Answer · A

δ = √(2ρ/(ωμ)) = √(2*1.7e-8/(2π*500e3*4πe-7)) = √(3.4e-8/(2π*500e3*4πe-7)). Calculate denominator: ω = 2πf = 3.14e6, μ = 4πe-7. Denominator = 3.14e6*1.256e-6 = 3.94. δ = √(3.4e-8/3.94) = √(8.63e-9) ≈ 9.3e-5 m = 0.093 mm. Wrong answers result from missing unit conversion or using wrong ω. Electromagnetics problems use Gauss's law for fields, Faraday's law for induced EMF, and Ampere's law for magnetic fields. Always identify the geometry (point charge, line, sheet, volume) to choose the correct Gauss/Ampere surface. Units and prefixes are critical in EM calculations.

Answer · B

V_GS - V_T = 6 - 2 = 4 V. If V_DS < V_GS - V_T (3 V < 4 V), the device is in the linear (triode) region. If V_DS > V_GS - V_T, it would be in saturation. A is incorrect (V_GS > V_T, so not cutoff); C is incorrect since V_DS < V_GS - V_T. D is not relevant here. For semiconductor device questions, remember that BJT operates in three regions (active, saturation, cutoff) while MOSFETs operate in three regions (cutoff, triode/linear, saturation). Check V_CE or V_DS relative to threshold to identify the region before computing currents.

Answer · B

To independently sign and seal plans, you must hold a PE license and have met all experience and education requirements set by your state. Distractors miss key requirements—A lacks PE, C lacks licensure, D is not a legal requirement. Ethics questions on the FE exam test knowledge of NSPE Code of Ethics and professional responsibilities. Engineers must hold public safety paramount and report unsafe conditions through proper channels. When in doubt between options, choose the one that prioritizes public safety while following legal and professional reporting procedures.

Answer · A

A time-invariant system must satisfy: time shift in input yields same time shift in output. For y(t) = x(2t), a shift in input does not yield a simple shift in output (time scaling is not time shift). Other options are time-invariant (delays and integrals with fixed limits are time-invariant). Linear systems questions test Laplace transforms, system stability, and impulse response. The ROC (region of convergence) determines causality and stability. For partial fraction expansion, identify if poles are real, complex, or repeated before decomposing.

Answer · B

log₁₀(x^3) = 9 ⇒ 3*log₁₀(x) = 9 ⇒ log₁₀(x) = 3 ⇒ x = 10^3 = 1000. Other choices are either not simplified or represent intermediate steps. Mathematics questions on the FE exam cover calculus, linear algebra, probability, and differential equations. For matrix problems, check for special properties (symmetric, diagonal, orthogonal) that simplify eigenvalue/inverse calculations. Probability problems often require identifying the distribution type (binomial, normal, Poisson) first.