Answer:
Intensity of a wave is Power per unit area.
Explanation:
The intensity of wave is defined as the power per unit area in the direction of motion of wave i.e.
[tex]I=\dfrac{P}{A}[/tex]
Also, the intensity of a wave is directly proportional to the square of its amplitude. Let a is the amplitude of a wave. So,
[tex]I\propto a^2[/tex]
The SI unit of power is watt and the SI unit of area is m². So, the SI unit of intensity is W/m². Hence, the correct option is (a) "Intensity of a wave is Power per unit area".
