It’s science, the theme is Characteristics of Electromagnetic and mechanical waves

1. False

2. True

3. True

4. False

5. True.

6. False.

7. True.

8. False.

9. False.

10. True.

11. False.

A wave is a disturbance in a medium which can propagate through a medium. But the net displacement of the medium remains zero.

The spreading of the wave from a slit or hole is proved through the double slit experiment showing interference between the two waves. So they do spread by passing through a hole.

A longitudinal wave is what is seen when a stone is thrown into a pond. The ripples created are the compression points and the areas between the two ripple is called the rarefaction point.

Amplitude is defined as the maximum displacement of a particle in wave from its mean position. So its not distance between two compression points.

2nd law of reflection states that the angle of incidence is equal to angle of reflection.

An electromagnetic wave doesn't need a matter to get transferred. Its the electric field and magnetic field vibrating at same interval but in 90°to each other.

Mechanical wave needs matter to transfer energy. So it cannot travel through space.

Decibel is the unit of intensity of sound. Unit of frequency is hertz or cps.