Waves

Sounds are produced due to ...................

• vibration of medium particles.

• electromagnetic forces.

• electrostatic forces.

• wave motion.

Mechanical waves are characterized by..........................

• their speed is greater than that of electromagnetic waves.

• their speed is 300 millions m/sec.

• they need a medium to propagate through.

.....................wave is an example of mechanical waves.

• Water

• Light

• Radio

• Ultraviolet

All of the following are electromagnetic waves except the

• infrared rays.

• sound waves.

• visible light.

• ultraviolet rays.

We see lightning before hearing thunder because ..................

• lightning occurs before thunder.

• sound needs a medium to travel through.

• the speed of light is 340 m/sec

• the speed of light is much greater than that of sound.

The speed of both.............................. in space equals 300 million m/sec.

• sound and light

• X-rays and gamma rays

• infrared rays and water waves

• ultraviolet rays and sound waves

Which grade are you ?

• 7

• 6

• 8

• 4

What do you like to watch ?

• Tik tok

• Youtube

• Netflix

• None