# Physics Revision Notes for Class 12 for Chapter 8 Electromagnetic Waves

Maxwell formulated a set of equations involving magnetic and electric field, their sources, charge and current densities. These equations are known as Maxwell’s equations. The most important prediction to emerge from these equations is the existence of electromagnetic waves which are a time-varying electric field and magnetic fields coupled together. In the CBSE class 12 Physics Chapter 8 Electromagnetic waves, the following topics are discussed:

• The need for displacement current and its consequences
• A descriptive account of electromagnetic waves
• The broad spectrum of electromagnetic waves stretching from γ rays ( having a wavelength of 10-12 m) to radios waves ( wavelength of 106 m)

Avail the CBSE class 12 physics notes for Chapter 8 Electromagnetic Waves provided below.

## Frequently asked Questions on CBSE Class 12 Physics Notes Chapter 8: Electromagnetic Waves

Q1

### What are the uses of ‘Infrared rays’?

Infrared rays are widely used for cosmetic applications such as for treating skin injuries, smoothing of wrinkles, reducing the occurrence of dandruff, blackheads, etc.

Q2

### What are the uses of ‘Electromagnetic’ waves?

Electromagnetic waves have a vast range of practical everyday applications that includes such diverse uses as communication by cell phone and radio broadcasting, WiFi, cooking, vision, medical imaging, and treating cancer.

Q3

### What is a ‘Displacement current’?

The displacement current was named as current because it is similar to conduction current. displacement current is the current due to the changing of the electric field inside the plate of the capacitor.