Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Paper format. National Exams, May 2016 — 07-Elec-A7 Electromagnetics. Three hours, closed book; one of two approved calculators permitted. Eight questions, all of equal value (20 marks each). The rubric states that any five questions constitute a complete paper and that only the first five presented are marked — all eight are worked here, because this set is a study resource rather than a sat examination.
Constants. The paper prints $\varepsilon_0 = 8.85\times10^{-12}\ \text{F/m}$ and $\mu_0 = 4\pi\times10^{-7}\ \text{H/m}$ as aids. Its own numbers imply the classroom values $c = 3.00\times10^{8}\ \text{m/s}$ and $\eta_0 = 120\pi = 377\ \Omega$: the offset in Question 3 is exactly $\lambda/8$ only if $\lambda = 3.00\ \text{cm}$ at 10 GHz, and the 2.25 cm guide of Question 4 places a cutoff exactly on 20 GHz only for the same value. Those are the constants used throughout; the more precise values shift every field and guide wavelength here by less than 0.3 %, and the one place where the difference matters is flagged in Question 4.
Reference texts. D. M. Pozar, Microwave Engineering, 4th ed., §2.1–2.7 (transmission-line theory, standing waves, impedance transformation). M. N. O. Sadiku, Elements of Electromagnetics, 7th ed., ch. 11 (transmission lines) and ch. 12 (waveguides). W. H. Hayt and J. A. Buck, Engineering Electromagnetics, 9th ed., ch. 10–11 (transmission lines, uniform plane waves). F. T. Ulaby and U. Ravaioli, Fundamentals of Applied Electromagnetics, 8th ed., ch. 2 and ch. 7 (line transients, wave polarisation). C. A. Balanis, Antenna Theory: Analysis and Design, 4th ed., ch. 4 (the infinitesimal/short current element).
