Question

Assertion (A): The distance between 5 consecutive compressions in a sound wave is 5 cm. So, the wavelength of sound wave is 1.25 cm.

Reason (R): The length between 2 consecutive compressions equals the wavelength, hence 1 wavelength equals $$\frac{5}{4} \text{ cm}$$.

Options

• If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.

• If both Assertion and Reason are true, but Reason is not correct explanation of the Assertion.

• If Assertion is true, but the Reason is false.

• If Assertion is false, but the Reason is true.

Answer 1

If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.

Explanation:

Assertion (A) is true. Five consecutive compressions contain 4 wavelength intervals. Therefore,

\[ 4\lambda = 5\text{ cm} \]

\[ \lambda=\frac{5}{4}\]

= 1.25 cm

Reason (R) is true. The distance between two consecutive compressions is one wavelength. Hence, if 4 such intervals occupy \(5\text{ cm}\), then

\[ \lambda=\frac{5}{4}\text{ cm}\]

= 1.25 cm

Therefore, both A and R are true, and R correctly explains A.