Conceptual Questions for Class 12 Physics Chapter 8 Electromagnetic Waves

Here we are providing conceptual questions based on class 12 physics chapter 8 electromagnetic waves. These questions are prepared by experts and are very useful from exam point of view. Students can practice these questions for scoring better marks in the exam.

Conceptual Questions for Class 12 Physics Chapter 8 Electromagnetic Waves

Hello students, in this article we are providing conceptual questions for class 12 physics chapter 8 electromagnetic waves. Students are suggested to go through each and every question for better understanding of the chapter.

Q.1. What is displacement current due to?

Solution. Displacement current exists due to a time-varying electric field or changing electric flux.

Q.2. Is the steady electric current the only source of magnetic field? Justify your answer.

Solution. No, displacement current also produces a magnetic field between the capacitor plates.

Q.3. What evidence is there that sound is not electromagnetic in nature?

Solution. Sound waves require an inertial medium for their propagation which shows that sound waves are mechanical in nature and not electromagnetic.

Q.4. What does an electromagnetic wave consist of? On what factors does its velocity in vacuum depend?

Solution. An electromagnetic wave consists of electric and magnetic fields, oscillating sinusoidally both in time and space. The two fields are perpendicular to each other as well as to the direction of propagation of the wave.

The velocity of an e.m. wave in vacuum depends on its performability (μ₀) and permittivity (ε₀).

Q.5. What oscillates in electromagnetic waves? Are these waves transverse or longitudinal?

Solution, (i) In e.m. waves, electric and magnetic fields oscillate in mutually perpendicular directions.

(ii) These waves are transverse in nature.

Q.6. A capacitor of capacitance C, is being charged up by connecting it across a d.c. voltage source of voltage V. How do the conduction and displacement currents, in this set-up compare with each other

(a) during the charging up process?

(b) after the capacitor gets fully charged?

Solution. By the property of continuity,

(a) Conduction current

= Displacement current

= a non-zero value, during the charging up process.

(b) Conduction current

= Displacement current

= 0, after the capacitor gets fully charged.

Q.7. If you find closed loops of B in a region in space, does it necessarily mean that actual charges are flowing across the area bounded by the loops?

Solution. Not necessarily. A displacement current (such as that between the plates of a capacitor that is being charged) can also produce loops of B, where charges do not flow actually.

Q.8. What feature of electromagnetic waves led Maxwell to conclude that light itself is an electromagnetic wave?

Solution. The emergence of the speed of light from purely electromagnetic consideration led Maxwell to conclude that light waves are electromagnetic in nature.

Q.9. What is the ratio of speed of infrared and ultraviolet rays in vacuum?

Solution. Ratio = 1, because the speed of an electromagnetic wave in vacuum is independent of its wavelength or frequency.

Q.10. Out of microwaves, ultraviolet rays and infra-red rays, which radiation will be most effective for emission of electrons from a metallic surface.

Solution. Ultraviolet rays are most effective for photoelectric emission because they have highest frequency and hence most energetic.

Importance of conceptual questions for class 12 physics

Conceptual questions are of utmost importance in Class 12 Physics for several reasons. These questions focus on understanding the fundamental principles and concepts rather than just rote memorization of equations and formulas. Here are some reasons why conceptual questions are crucial in Class 12 Physics:

Deep understanding: Conceptual questions require students to grasp the underlying principles and theories behind physical phenomena. This leads to a deeper understanding of the subject, making it easier to apply the knowledge to various problem-solving scenarios.
Critical thinking: When students tackle conceptual questions, they are encouraged to think critically and analytically. These questions often involve complex scenarios that demand logical reasoning and creative thinking to arrive at the right answers.
Problem-solving skills: Conceptual questions challenge students to solve unfamiliar and intricate problems. As a result, their problem-solving skills are honed, preparing them to tackle more advanced scientific challenges in the future.
Application of concepts: By answering conceptual questions, students learn to apply theoretical concepts to practical situations. This bridges the gap between theory and real-world applications, fostering a holistic understanding of Physics.
Better exam preparation: Class 12 board exams and competitive entrance exams often include conceptual questions. Preparing for such questions not only improves performance in exams but also sets a strong foundation for further studies in physics-related fields.
Enhanced retention: Understanding concepts leads to better retention of knowledge. Unlike rote memorization, conceptual understanding stays with students for a long time, making it easier to build on that knowledge in the future.
Encouraging curiosity: Conceptual questions often pique students’ curiosity and encourage them to explore the subject further. This can spark an interest in Physics as a whole, leading to a lifelong passion for the subject.
Formulating connections: Conceptual questions help students make connections between different topics and subfields within Physics. This interconnected knowledge is essential for a comprehensive understanding of the subject.
Learning from mistakes: When students attempt conceptual questions, they may make mistakes. However, these mistakes provide valuable learning opportunities, as they highlight areas that need further clarification and understanding.
Building confidence: Successfully answering conceptual questions gives students a sense of accomplishment and boosts their confidence in their Physics abilities.

Conceptual Questions for Class 12 Physics Chapter 8 Electromagnetic Waves

Conceptual Questions for Class 12 Physics Chapter 8 Electromagnetic Waves

Importance of conceptual questions for class 12 physics

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