Question

the frequency of the radiation having wave number 10​

Answer 1

Given that Frequency of radiation = 4 *10^14 Hz = 4 *10^14 s^-1

We know that required formula is:

Wave length = Speed / Frequency

Wave number = 1/Wavelength

Therefore Wave number = Frequency / speed

Speed of light is 3 * 10^8 m/s

Wave number = 4 *10^14 / 3 * 10^8 = 1.33 * 10^6 m^-1

Answer is 1.33 * 10^6 metre