What is the ratio of velocities of light rays of wavelength `5,000 overset @ A` and `7,000 overset @A` in vacuum?

What is the ratio of velocity of light of wavelengths 4000 oversetcircA and 8000 oversetcircA in vacuum?

Give the ratio of velocities of light rays of equal wavelength in vacuum.

Give the ratio of velocities of light rays of wave length 4000A^@ and 6000^@ in vacuum.

The value of velocity of light in vacuum is:

What is the ratio of speed of infrared rays and ultraviolet rays in vacuum?

What physical quantity is the same for X-rays of wavelength 10^-10 m, red light of wavelength 6800 overset @A and radiowaves of wavelength 500 m?