Question

Give the ratio of velocity of light rays of frequency 5 hertz and 2.5 hertz

Answer 1

Answer:

2:1

Explanation:

Let the velocity of the two light rays represented by v1 and v2 respectively.

Since, both is the lighr rays, so the wavelength of both the waves will be same.

Since the frequency of the first wave is (f1) = 5 hertz

and , the frequency of the second wave is (f2) = 2.5 hertz.

Since, the velocity is given by $velocity = wavelength \times frequency$

∴ $v1 = wavelength \times f1$

∴ $v1 = wavelength \times 5$...........(1)

and

∴ $v2 = wavelength \times f2$

∴ $v2 = wavelength \times 2.5$...........(2)

Now, dividing (1) and (2),  we get

$\frac{v1}{v2} = \frac{5}{2.5}$

$\frac{v1}{v2} =  \frac{2}{1}$

∴ v1 : v2 = 2 : 1

∴ The ratio of the velocities be 2 : 1