GATE 2023 EC Q20 | Phase vs Group Velocity in a Lossless Dielectric | Electromagnetics Solved

GATE 2023 EC — Question 20 (1 mark, MCQ), solved step by step and verified. QUESTION: Consider a narrow band signal, propagating in a lossless dielectric medium (ε_r = 4, μ_r = 1), with phase velocity v_p and group velocity v_g. Which of the following statement is true? (c is the velocity of light in vacuum.) A) v_p ＞ c, v_g ＞ c B) v_p ＜ c, v_g ＞ c C) v_p ＞ c, v_g ＜ c D) v_p ＜ c, v_g ＜ c ANSWER: D) v_p ＜ c, v_g ＜ c (matches the official answer key) Chapters: 0:00 The question (official GATE paper) 0:22 Step 1: Write the dispersion relation 0:43 Step 2: Phase velocity and group velocity 1:03 Step 3: Compare with c 1:25 Verified live on SiliconVerify Plane Waves & Properties 2:08 Outro Don't just watch — replay this exact solve on the tool and change the numbers: https://siliconverify.com/emft-waves.... (free, no signup) Source: official GATE 2023 EC question paper, IIT Kanpur. #GATE2023 #GATEEC #Electromagnetics #GATEpreparation #GATEPYQ