# Confirmed Errata – Study Guide for FE Electrical and Computer CBT Exam – Second Edition

### Corrections – Problems Section:

Problem 5.3 b) Calculate Young’s Modulus of this wire if its diameter is **2 mm**.

Problem 8.2 c) Voltage source is 120 VAC.

Problem 9.3 h) In Option B, -209 should be 209.

Problem 11.2 e) Option B = 23.5/5.7° Ω

### Corrections – Solutions Section:

Problem 1.1 a) According to the solution x = -2. Since the base 3 is positive (3>0), the base 3 raised to the power of any real number must be positive. So the number x must be positive (x>0). x = -2 will not be a valid solution in logarithmic domain.

Problem 1.4 k) Directrix of a parabola centered at origin (i.e. h = k= 0) is x = -p/2 as shown in the solution. But, the parabola given in the problem is not centered at origin. In this case, directrix should be given by **x = h – p/2 = 2 – 2/2 = 1**

Problem 2.3 b) **µ = E[x] = 3.18 is correct** but the solution in Study Guide uses arithmetic average instead of expected value. This will result in **σ = 0.63.**

Problem 2.3 g) $53,338 ≤ µ ≤ $56,662

Problem 5.3 b) Young’s Modulus units of measurement is N/m²

Problem 7.5 c) |Z| = √(500² + 100²) = 509.9Ω θ = arctan(100/500) = -11.4°

Z = **509.9/-11.4° Ω ** I = V/Z = 70.7/509.9 = **0.138 /-11.4° A**

Problem 7.5 e) Z = (5 – j10) **–** [(j100)(20 + 5j)] /[(20 – 5j)(20 + 5j)]

Study Guide solution shows + sign instead of – sign between the two terms.

Problem 9.3 h) Final answer should indicate -209 as 209 because C2 = 209

Problem 11.2 e) Z_load = **23.5 /5.7° Ω**