Question

A wave from a source having power 1 watt is incident on a surface of area 200 m\(^2\). What is the intensity of the wave?

• A. \( I = \frac{P}{A} = \frac{1}{200} \)
• B. \( I = P \times A \)
• C. \( I = P + A \)
• D. \( I = \frac{A}{P} \)

Hint:

Intensity is always the power per unit area. To calculate intensity, divide the power by the area over which the wave is distributed.

Answer 1

The Correct Option is A

The intensity of a wave is defined as the power per unit area, and it is given by the formula: \[ I = \frac{P}{A} \] where \( I \) is the intensity, \( P \) is the power of the wave, and \( A \) is the area over which the power is distributed. Given that: - Power \( P = 1 \) watt - Area \( A = 200 \) m\(^2\) Substituting the values into the formula: \[ I = \frac{1}{200} = 0.005 \text{ watts per square meter (W/m}^2\text{)} \] Thus, the intensity of the wave is \( 0.005 \) W/m\(^2\).