Class 12 Physics MCQ Chapter 8 Electromagnetic Waves
Searching for high-quality Class 12 Physics MCQ Chapter 8 Electromagnetic Waves English Medium questions for AHSEC exam preparation? This article brings together a valuable collection of multiple-choice questions (MCQs) with answers to help students revise the chapter efficiently and improve their examination performance.
The chapter Electromagnetic Waves explains the nature, properties, and applications of electromagnetic radiation. Students will learn about the generation of electromagnetic waves, electromagnetic spectrum, radio waves, microwaves, infrared rays, visible light, ultraviolet rays, X-rays, and gamma rays. The chapter also highlights the practical uses of different electromagnetic waves in communication, medicine, industry, and scientific research.
These MCQs are prepared according to the latest AHSEC syllabus and are designed to help students understand key concepts, strengthen their theoretical knowledge, and become familiar with board exam question patterns. Regular practice can significantly improve accuracy, retention, and confidence when answering objective questions.
Whether you are revising important topics before an examination or looking for extra practice material, these Chapter 8 MCQ solutions will help you build a strong understanding of Electromagnetic Waves and score higher marks in Physics.
Part: I
Electromagnetic Waves
VSA & MCQ
I. Very Short Answer Questions
Q. What are electromagnetic waves?
Ans: Electromagnetic waves are transverse waves consisting of oscillating electric and magnetic fields.
Q. Who predicted electromagnetic waves?
Ans: James Clerk Maxwell.
Q. What is the nature of electromagnetic waves?
Ans: Transverse.
Q. What is the speed of electromagnetic waves in vacuum?
Ans: c = 3 × 10⁸ m/s.
Q. What is the relation between speed, frequency and wavelength?
Ans: c = νλ.
Q. Do electromagnetic waves need a medium?
Ans: No.
Q. What is the direction of propagation of EM waves?
Ans: Perpendicular to both electric and magnetic fields.
Q. What is the range of electromagnetic spectrum?
Ans: From radio waves to gamma rays.
Q. What are radio waves used for?
Ans: Communication.
Q. What are microwaves used for?
Ans: Radar and cooking.
Q. What are infrared waves used for?
Ans: Heating and remote controls.
Q. What is visible light?
Ans: Part of spectrum visible to human eye.
Q. What are ultraviolet rays?
Ans: High-frequency waves causing chemical effects.
Q. What are X-rays used for?
Ans: Medical imaging.
Q. What are gamma rays used for?
Ans: Cancer treatment.
Q. What is energy of EM wave?
Ans: E = hν.
Q. What is momentum of EM wave?
Ans: p = E / c.
Q. What is intensity of wave?
Ans: Power per unit area.
Q. What is displacement current?
Ans: Current due to changing electric field.
Q. What is Maxwell’s correction?
Ans: Addition of displacement current term.
Q. What is electromagnetic spectrum?
Ans: Arrangement of EM waves by frequency.
Q. What is wavelength of visible light?
Ans: 400–700 nm.
Q. What is frequency of EM waves?
Ans: Number of oscillations per second.
Q. What is amplitude of EM wave?
Ans: Maximum field strength.
Q. What is polarization?
Ans: Restriction of vibration to one direction.
Q. What is Poynting vector?
Ans: Represents energy flow.
Q. What is relation between E and B?
Ans: E = cB.
Q. What is radiation pressure?
Ans: Pressure exerted by EM waves.
Q. What is coherence?
Ans: Constant phase relation.
Q. What is monochromatic wave?
Ans: Single frequency wave.
II. Multiple Choice Questions
Q. EM waves are:
(a) Longitudinal
(b) Transverse
(c) Stationary
(d) Random
Ans: (b)
Q. Speed of EM waves is:
(a) 3 × 10⁶
(b) 3 × 10⁸
(c) 3 × 10¹⁰
(d) 3 × 10⁵
Ans: (b)
Q. EM waves need medium:
(a) Yes
(b) No
(c) Sometimes
(d) Only in solids
Ans: (b)
Q. Relation is:
(a) c = νλ
(b) c = ν/λ
(c) c = λ/ν
(d) None
Ans: (a)
Q. Visible light range is:
(a) 100–200 nm
(b) 400–700 nm
(c) 700–1000 nm
(d) 1–10 nm
Ans: (b)
Q. X-rays are used in:
(a) Cooking
(b) Imaging
(c) Communication
(d) Heating
Ans: (b)
Q. Gamma rays are:
(a) Low frequency
(b) High frequency
(c) Medium
(d) None
Ans: (b)
Q. E and B are:
(a) Parallel
(b) Perpendicular
(c) Same
(d) Zero
Ans: (b)
Q. EM waves carry:
(a) Energy
(b) Momentum
(c) Both
(d) None
Ans: (c)
Q. Displacement current is due to:
(a) Charges
(b) Changing electric field
(c) Magnetic field
(d) Voltage
Ans: (b)
Q. Assertion: EM waves are transverse. Reason: Fields oscillate perpendicularly.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (a)
Q. Assertion: EM waves do not need medium. Reason: They require particles to propagate.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (c)
Q. Assertion: Speed is constant in vacuum. Reason: Depends only on ε₀ and μ₀.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (a)
Q. Assertion: E = cB. Reason: Electric and magnetic fields are parallel.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (c)
Q. Assertion: X-rays penetrate matter. Reason: They have low frequency.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (c)
Q. Assertion: Displacement current produces magnetic field. Reason: It is due to changing electric field.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (a)
Q. Assertion: Gamma rays have highest frequency. Reason: They have longest wavelength.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (c)
