Class 12 Physics Important Chapter 8 Electromagnetic Waves

Class 12 Physics Important Chapter 8 Electromagnetic Waves Solutions English Medium As Per The New Syllabus to each chapter is provided in the list so that you can easily browse through different chapters ASSEB Class 12 Physics Important Chapter 7 Alternation Current Solutions in English and select need one. NCERT Class 12 Physics Additional Solutions Download PDF. HS 2nd Year Physics Important Solutions.

Class 12 Physics Important Chapter 8 Electromagnetic Waves

Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. CBSE Class 12 Physics Additional Question Answer are part of All Subject Solutions. Here we have given HS 2nd Physics Important Solutions English Medium for All Chapters, You can practice these here.

Electromagnetic Waves

Chapter: 8

IMPORTANT QUESTION AND ANSWER

Answer The Following Questions:

1. State two applications of ultraviolet radiations.

Ans. Ultraviolet radiations are used (i) to preserve the food stuff; (ii) for sterilising the surgical instruments.

2. State two characteristics of on electromagnet wave.

Ans. (i) The electromagnetic waves travel in free space with a speed of 3 x 10 m/s.

(ii) They are transverse in nature.

3. Write two uses of X-rays.

Ans. (i) X-rays are used as a diagnostic tool in medicine.

(ii) In the treatment of certain forms of cancer.

4. Name the electromagnetic radiation which can be produced by a klystron or a magnetron value.

Ans. Electromagnetic wave produced by klystron or a magnetron value is micro-wave.

5. What is electromagnetic spectrum?

Ans. The orderly distribution of electromagnetic radiations of all types according to their wavelength or frequency into distinct groups having widely differing properties is called electromagnetic spectrum.

6. Why are infrared waves called heat waves?

Ans: Infrared waves are called heat waves because water molecules and other molecules like CO₂ and NH₃ absorb them easily, which increases thermal motion and thus heats the material and its surroundings.

7. Out of the four Maxwell’s equations, which equation establishes the non-existence of magnetic monopole?

Ans: The equation ∮ B · dA = 0 (Gauss’s Law for Magnetism) establishes the non-existence of magnetic monopoles.

8. Write down the Gauss’s Law of magnetism as written in Maxwell’s Equations.

Ans: ∮ B · dA = 0 is the Gauss’s Law for magnetism, indicating that the net magnetic flux through any closed surface is zero.

9. Name the portion of the electromagnetic spectrum in between ultraviolet and infrared regions.

Ans: Visible light lies between the ultraviolet and infrared regions in the electromagnetic spectrum.

10. What is the radiation pressure on earth’s surface?

Ans: The textbook does not state a specific value for radiation pressure, but it is implied through the discussion that light (electromagnetic waves) carry energy and momentum, and thus exert a small radiation pressure on surfaces like the Earth’s surface. The exact value depends on the intensity of the incoming radiation.

11. Write down the four Maxwell’s equations.

Ans: In vacuum, the four Maxwell’s equations are:

(i) Gauss’s Law for Electricity:

(ii) Gauss’s Law for Magnetism:

(iii) Faraday’s Law of Electromagnetic Induction:

(iv) Ampere–Maxwell Law:

12. How does a charge ‘q’ oscillating at certain frequency produce electromagnetic waves?

Ans: An oscillating charge is an accelerating charge, and according to Maxwell’s theory, accelerated charges radiate electromagnetic waves. An oscillating charge produces a changing electric field, which generates a changing magnetic field, and this process continues — thus forming self-sustaining electromagnetic waves that propagate through space.