Question

When a wave enters into a rarer medium from a denser medium, the property of the wave which remains constant is:

• A. \text{Wavelength}
• B. \text{Frequency}
• C. \text{Velocity}
• D. \text{Amplitude}

Hint:

The frequency of a wave remains unchanged when moving between media. However, wavelength and speed may change.

Answer 1

The Correct Option is B

Step 1: Understanding Wave Properties When a wave passes from one medium to another, its speed and wavelength change, but its frequency remains the same. Step 2: Explanation Using the wave equation: \[ v = f \lambda \] where \( v \) is velocity, \( f \) is frequency, and \( \lambda \) is wavelength. - In a new medium, \( v \) and \( \lambda \) may change, but \( f \) remains constant because it is determined by the source of the wave. \bigskip

Answer 2

When a wave passes from one medium to another, certain properties of the wave may change while others remain constant.

Given:
- Wave moving from a denser medium to a rarer medium.

Key properties of waves:
- Frequency (\( f \))
- Wavelength (\( \lambda \))
- Speed (\( v \))

When a wave crosses the boundary between two media:
- The frequency \( f \) remains constant because it is determined by the source of the wave.
- The speed \( v \) changes depending on the medium.
- The wavelength \( \lambda \) changes accordingly, since \( v = f \lambda \).

Therefore, the property of the wave which remains constant when it enters a rarer medium from a denser medium is:
\[ \boxed{\text{Frequency}} \]