Question

A visible violet light emits light with a wavelength of 4.00 × 10-7 m. Calculate the frequency of the violet light.

Answer 1

For any wave,
Frequency = (speed) / (wavelength)

= (3 x 10⁸ m/s) / (4 x 10⁻⁷ m)

= (3/4 x 10¹⁵) ( m / m - s )

= (0.75 x 10¹⁵) /sec

= 7.5 x 10¹⁴ Hz

= 750,000 GHz

Answer 2

Answer: The correct answer is
`f=75* 10^(13)` Hz.

Step-by-step explanation:

The expression of the wavelength in terms of the frequency is as follows;

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

Here, c is the speed of the light, f is the frequency of the wave and
`\lambda` is the wavelength of the wave.

It is given in the problem that a visible violet light emits light with a wavelength of 4.00 × 10-7 m.

Calculate the frequency of the violet light by rearranging the above expression.

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

Put
`c=3* 10^(8) m/s` and
`{\lambda }=4* 10^(-7)`.

`f=(3* 10^(8))/(4* 10^(-7))`

`f=75* 10^(13) Hz`

Therefore, the frequency of the violet light is
`f=75* 10^(13) Hz`.