Wave Length – The Minimum Distance in which a wave repeats itself is called its wavelength

• At the time Maxwell predicted the existence of electromagnetic waves, the
only familiar electromagnetic waves were the visible light waves.
• The existence of ultraviolet and infrared waves was barely established.
• By the end of the nineteenth century, X-rays and gamma rays had also been discovered.
• electromagnetic waves include visible light waves, X-rays, gamma rays, radio waves, microwaves, ultraviolet and infrared waves.
• The classification of em waves according to frequency is the electromagnetic
spectrum
• There is no sharp division between one kind of wave and the next.
• The classification is based roughly on how the waves are produced and/or detected.

Sound Free Lesson For Class 9th NCERT

Speed=Frequency ❌Wavelength.

• Remember More the wavelength less the frequency and vice versa.
• also try to remember the wavelength and the frequency can be found out