GATE 2026 Physics (PH) | MCQ Q11–Q20 | Detailed Solutions

Detailed video solutions to GATE 2026 Physics (PH) MCQ questions Q11 to Q20, explained step by step. Solutions by Santosh Kumar Sahu (IIT Madras). ⏱️ Chapters 0:00 Q11 – Maxwell's equations, plane EM waves 5:40 Q12 – Electrostatic boundary conditions (dielectrics) 12:39 Q13 – Hermitian operators (Postulates of QM) 18:16 Q14 – Vector calculus identity 20:38 Q15 – Time reversal of E and B 26:33 Q16 – Projectile with drag (Lagrangian formulation) 34:53 Q17 – Otto cycle (Laws of thermodynamics) 42:27 Q18 – Photon gas specific heat 48:09 Q19 – Polarization of EM waves 53:01 Q20 – Bose–Einstein condensation (chemical potential) ✅ Answer key Q11 (B) | Q12 (A) | Q13 (A) | Q14 (A) | Q15 (C) | Q16 (C) | Q17 (A) | Q18 (B) | Q19 (C) | Q20 (C) Topics covered: Electromagnetic Theory, Quantum Mechanics, Mathematical Physics, Classical Mechanics, Thermodynamics & Statistical Physics. If this helped, like, share with your GATE friends, and subscribe for more GATE Physics solutions. Drop your doubts in the comments. #GATE2026 #GATEPhysics #GATEPH #PhysicsMCQ #GATEPreparation