Question

What will be the ratio of wave lengths of two ultrasonic waves having freqencies 10*4 Hz and 1.5×10*4 Hz ,if speed of both the waves is same ?

Answer 1

1) ultra sonic sound property
wavelength = a (Lambada)
speed = V1
frequency = n1 = 10000Hz

2) ultra sonic sound property
wavelength = a1 (Lamba)
speed = V1
frequency = n2 = 1.5×10^4Hz = 15/10×10000 = 15000Hz

(V1/n1)/(V1/n2) = a/a1
V1/n1×n2/V1 = a/a1
n2/n1 = a/a1
15000/10000 = a/a1
15/10 = a/a1
3/2 = a/a1

so ratio of the wavelengths is = a : a2 = 3 : 2

Answer 2

Given - Frequency

Find - Ratio of wavelengths

Solution - The ratio of wavelength is 1.5:1.

The frequency and wavelength are related by the formula - c = f * lamda. In this formula, c is speed of light, f is frequency and lambda is wavelength.

Since speed of light is same, so, the formula will be -

F1 * lambda1 = F2 * lambda2

10⁴ * lambda1 = 1.5*10⁴ * lambda2

$\frac{lambda1}{lambda2} = \frac{1.5 \times {10}^{4} }{ {10}^{4} }$

$\frac{lambda1}{lambda2} = \frac{1.5}{1}$

Thus, the ratio of wavelength is 1.5:1.