Question

Light waves are propagating in vacuum. Derive the wave equation for the

associated magnetic field vector. On the basis of this equation, calculate the speed

of light​

Answer 1

Answer:

C = 1/8.85×10^−12 ×4π×10^−7 m/s

C =2.97*10^8 m/sec

C = 3*10^8 (approximately)

m/sec

Answer 2

Equation for speed of light is c = fλ

Explanation:

Let's take a wave traveling in the x-direction E = Ej, then B = Bk and j x k = i.  Electromagnetic waves are transverse waves.  

• The wave number is k = 2π/λ.
• Where λ is the wavelength of the wave.
• The frequency f of the wave is f = ω/2π.
• ω is the angular frequency.  
• The speed of a wave is obtained as the product of wavelength and frequency such as v = λf.

The speed of any electromagnetic waves in free space is the speed of light c = 3 x 10^8 m/s.

Electromagnetic waves can have any wavelength λ or frequency f as long as λf = c.