Question

Two waves $A$ and $B$ have wavelength $0.01A^o$ and $9000A^o$ respectively. Compare the speeds of these waves when they travel in vacuum.

• A. $1:9$
• B. $9:1$
• C. $1:1$
• D. None of the above

Answer 1

The correct option is C $1:1$

The electromagnetic spectrum consists of the full range of known electromagnetic waves, including gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves. All of these are produced by various forms of oscillating charges or currents. Electromagnetic waves are transverse waves which travel at the speed of light and involve oscillating electric and magnetic fields at right angles to each other.
Hence, the speeds of these waves when they travel in vacuum is same as the speed of visible light, that is, $3\times {10}^{8}m/s$. Therefore, the ratio of their speeds is $1:1$.