Question

What is the frequency, in hertz, of an electromagnetic wave with a wavelength of 625 nm?

Answer 1

Answer:- Frequency is
`4.80*10^1^4Hz` .

Solution:- The wavelength of electromagnetic radiation is given as 625 nm and we are asked to calculate the frequency. Frequency is inversely proportional to the wavelength and the formula used to calculate frequency when wavelength is given is:

`\\u =(c)/(\lambda )`

where,
`\\u` is frequency, c is speed of light and
`\lambda` is the wavelength.

Value of speed of light is
`(3.0*10^8m)/(s)` . We need to convert the given wavelength from nm to m.

`1nm=10^-^9m`

So,
`625nm((10^-^9m)/(1nm))`

=
`6.25*10^-^7m`

Let's plug in the values in the formula and calculate the frequency:

`\\u =(3.0*10^8m.s^-^1)/(6.25*10^-^7m)`

=
`4.80*10^1^4s^-^1` or Hz.

So, the frequency of the electromagnetic wave is
`4.80*10^1^4Hz` .