Question

4. If the speed of a wave is 380 m/s and its frequency is 1900 Hz, then the wavelength of the wave
will be:
(a) 20 m
(b) 0.2 m
(c) 200 m
(d) 2 m​

Answer 1

Given :-

Speed of the wave = 380 m/s

Frequency of the wave = 1900 Hz

To Find :-

The wavelength of the wave.

Analysis :-

Here we are given with the speed and the frequency of the wave.

In order to find the wavelength substitute the given values in the question such that velocity is equal to frequency multiplied by wavelength.

Solution :-

We know that,

• f = Frequency
• v = Velocity
• λ = Wavelength

Using the formula,

$\underline{\boxed{\sf Velocity=Frequency \times Wavelength}}$

Given that,

Velocity (v) = 380 m/s

Frequency (f) = 1900 Hz

Substituting their values,

⇒ v = fλ

⇒ 380 = 1900 × λ

⇒ λ = 380/1900

⇒ λ = 38/190

⇒ λ = 2/10 = 0.2 m

Therefore, the wavelength of the wave is (b) 0.2 m.

Answer 2

Answer:

Given :-

• The speed of a wave is 380 m/s and its frequency is 1900 Hz.

To Find :-

• What is the frequency of the wave.

Formula Used :-

★ λ = v ÷ f ★

where,

• λ = Wavelength
• v = Velocity
• f = Frequency

Solution :-

Given :

• Velocity = 380 m/s
• Frequency = 1900 Hz

According to the question by using the formula we get,

↦ λ = v ÷ f

↦ λ = 380 ÷ 1900

↦ λ = 38 ÷ 190

➠ λ = 0.2 m

∴ The wavelength of the wave is 0.2 m .

Hence, the correct options is option no (b) 0.2 m.