Electromagnetic Waves and Communication System — Class 11 MCQs with Answers
Class 11 CBSE Physics · Chapter 307
40 practice questions · 20 Easy · 20 Medium · Updated
Practise the most important Class 11 CBSE Physics questions from Chapter 307, "Electromagnetic Waves and Communication System". You get 4 timed quizzes made from 40 NCERT-based MCQs, with answers and explanations. The questions are split into 20 Easy and 20 Medium. Warm up on the basics, then move on to the exam-level questions that set top scorers in CBSE & Maharashtra HSC Board exams, JEE Main, MHT-CET, JEE Advanced and NEET UG apart.
To score well in "Electromagnetic Waves and Communication System", focus on numericals, derivations and applying concepts. Each MCQ here is timed and uses exam-style marking (+4 correct, −1 wrong, 0 skipped). This trains you to stay accurate under time pressure, as real papers need. Every question has a short explanation, so a wrong answer becomes a quick lesson. It is the fastest way to fix gaps before a test.
Use this chapter for focused revision. Start with the Easy set to check your basics on Electromagnetic Waves and Communication System, then move to Medium to practise applying them. Your accuracy, streaks and XP save automatically. This chapter also adds to your overall Class 11 Physics mastery score. 6 sample questions are solved in full below, with the answer and a worked explanation. Sign in free to start practising.
Key concepts: Electromagnetic Waves and Communication System (Class 11 Physics)
Maxwell's completion of electromagnetism and its consequence: displacement current and the corrected Ampere law, the prediction that light is an electromagnetic wave, the properties that follow — transverse character, mutual perpendicularity of E and B, and the energy and momentum a wave carries — and the full electromagnetic spectrum with the uses of each band.
- Displacement current
- Maxwell's insight that a changing electric field acts as a current, resolving the inconsistency of Ampere's law in the gap of a charging capacitor.
- Ampere-Maxwell law
- Adds displacement current to conduction current in Ampere's law, making the set of electromagnetic equations complete and self-consistent.
- Prediction of EM waves
- Maxwell's equations predict self-sustaining waves travelling at 1/√(μ₀ε₀), a value matching the measured speed of light — establishing light as an EM wave.
- Nature of EM waves
- Oscillating electric and magnetic fields, mutually perpendicular and both perpendicular to the direction of propagation. No medium is needed.
Electromagnetic Waves and Communication System — important questions & MCQs with answers (Class 11 Physics)
6 solved questions from this chapter's difficulty levels, each with its answer and explanation. The other 34 are timed and scored when you sign in.
- Q1Easy
Speed of EM waves in vacuum:
A.3 × 10⁸ m/s✓ CorrectB.3 × 10⁶ m/sC.10⁸ m/sD.10¹⁰ m/sAnswer: A. 3 × 10⁸ m/s
Explanation: c ≈ 3×10⁸ m/s.
- Q2Easy
The wavelength range of visible light is approximately:
A.700 nm–1 mmB.1–10 nmC.400–700 nm✓ CorrectD.10 cm–1 mAnswer: C. 400–700 nm
Explanation: Violet ~400 nm to red ~700 nm.
- Q3Easy
EM waves are:
A.Sound wavesB.LongitudinalC.MechanicalD.Transverse✓ CorrectAnswer: D. Transverse
Explanation: E and B perpendicular to direction of propagation.
- Q4Medium
In an EM wave the peak electric field is E₀ = 60 V/m. The peak magnetic field B₀ is approximately:
A.60 TB.2.0 × 10⁻⁵ TC.2.0 × 10⁻⁹ TD.2.0 × 10⁻⁷ T✓ CorrectAnswer: D. 2.0 × 10⁻⁷ T
Explanation: B₀ = E₀/c = 60/(3×10⁸) = 2.0×10⁻⁷ T.
- Q5Medium
Increasing frequency order:
A.Radio < Microwave < IR < Visible < UV < X-ray < γ✓ CorrectB.γ < X-rayC.Visible < RadioD.All sameAnswer: A. Radio < Microwave < IR < Visible < UV < X-ray < γ
Explanation: Standard EM spectrum.
- Q6Medium
Average energy density of an EM wave with E_rms = 1 V/m in vacuum is approximately:
A.8.85 × 10⁻¹⁸ J/m³B.8.85 × 10⁻⁶ J/m³C.8.85 × 10⁻¹² J/m³✓ CorrectD.1 J/m³Answer: C. 8.85 × 10⁻¹² J/m³
Explanation: u = ε₀E_rms² = 8.85×10⁻¹² × 1² J/m³.
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Start this chapter free →Electromagnetic Waves and Communication System — FAQs
What are the key concepts in Class 11 Physics Electromagnetic Waves and Communication System?+
Maxwell's completion of electromagnetism and its consequence: displacement current and the corrected Ampere law, the prediction that light is an electromagnetic wave, the properties that follow — transverse character, mutual perpendicularity of E and B, and the energy and momentum a wave carries — and the full electromagnetic spectrum with the uses of each band. Key ideas include Displacement current, Ampere-Maxwell law, Prediction of EM waves, Nature of EM waves.
What does Class 11 Physics Chapter 307 (Electromagnetic Waves and Communication System) cover on XamBaaz?+
It has 40 NCERT-based MCQs on "Electromagnetic Waves and Communication System": 20 Easy and 20 Medium. Together they make 4 timed quizzes, and you never get the same set twice. Every question has an instant explanation. They help you prepare for CBSE & Maharashtra HSC Board exams, JEE Main, MHT-CET, JEE Advanced and NEET UG.
Are these "Electromagnetic Waves and Communication System" questions free to practise?+
Yes. Sign in with Google to practise "Electromagnetic Waves and Communication System" free. Full unlimited access is ₹999/year on a launch offer until 1 December 2026. No chapter is charged separately.
How should I revise "Electromagnetic Waves and Communication System" for the exam?+
Start with the Easy quiz to check your basics, then try Medium to practise applying them. There are 4 timed quizzes on this chapter, so you can come back for a fresh set instead of one you have seen. Read each explanation, retry the questions you miss, and track your accuracy until it stays high.
Are these "Electromagnetic Waves and Communication System" MCQs available with answers?+
Yes. 6 sample questions are shown here in full, each with the correct option and a step-by-step "Why" explanation. Sign in free with Google to start practising, with instant scoring.
Is there negative marking in the "Electromagnetic Waves and Communication System" quizzes?+
Yes. The timed quizzes use exam-style marking: +4 for a right answer, −1 for a wrong one and 0 for a skip, the same negative marking as JEE Main, JEE Advanced and NEET UG. MHT-CET and CBSE board papers have no negative marking. Our mocks for those are scored their way.
What are the important questions from Electromagnetic Waves and Communication System (Class 11 Physics)?+
The questions that matter most test Displacement current, Ampere-Maxwell law, Prediction of EM waves, Nature of EM waves. This page shows 6 solved important MCQs with answers and explanations; all 40 questions on the chapter are available as timed quizzes once you sign in.
Is there an online quiz for Electromagnetic Waves and Communication System?+
Yes — Class 11 Physics Electromagnetic Waves and Communication System has timed online quizzes at Easy and Medium levels, with instant scoring and a worked explanation on every question. The first quiz on the chapter is free.