What is the wavelength of a light?

Question

What is the wavelength of a light that has a frequesncy of 3 MHz?
a. 9*10 to the 14th Hz
b. 1*10 to the 14th m
c. 9*10 to the 14th m
d. 100 m
e. 0.01 m

Answer 1

I assume the light is in vacuum or air.

Speed of light = 3E8 m/s
"E" means 10 to the __ power.

So we have 3e6 cycles in one second.
And also 3e8 meters in one second.
So each cycle takes up 3e8 / 3e6 = 100 meters

That's not visible light, that is a low frequency radio wave.

Answer 2

wave length= 3*10^8/ 3*10^6= 100m
so the answer is D

Answer 3

using the wave equation, v=f*lamda,

if the speed of light is 299,792,458 m/s and f=3,000,000 hz

then lamda = v / f

= 299,792,458 / 3,000,000

= 99.930819333 m

So the answer looks like d, 100m

However, that's definitely not in the visible range of wavelengths. 99m is a very long wavelength. We are looking here at a radio frequency.

christo

Answer 4

1* 10^2 m = 100 m (Radio wave)


Click below to veify.

Answer 5

I know that wavelength x frequency = c. So, the desired wavelength will be given by c/frequency = 300000000/3000000 = 100 m. The correct answer is d.

Answer 6

That's not light -- it's a radio wave .... 100 m