Waves and Technology

Based on the electromagnetic spectrum, which of the following do radio waves have?

• High frequency and long wavelength

• High frequency and short wavelength

• Low frequency and long wavelength

• Low frequency and short wavelength

Based on the electromagnetic spectrum, what do X-rays have?

• Low frequency and long wavelength

• High frequency and long wavelength

• Low frequency and short wavelength

• High frequency and short wavelength

Interference is when...

• A wave loses energy as it travels through a medium.

• A wave bounces off the boundary between one medium and another.

• A wave bends as it moves from one medium to another.

• Two waves overlap and combine.

Refraction is when...

• A wave loses energy as it travels through a medium.

• A wave bounces off the boundary between one medium and another.

• A wave bends as it moves from one medium to another.

• Two waves overlap and combine.

Attenuation is when...

• A wave loses energy as it travels through a medium.

• A wave bounces off the boundary between one medium and another.

• A wave bends as it moves from one medium to another.

• Two waves overlap and combine.

Reflection is when...

• A wave loses energy as it travels through a medium.

• A wave bounces off the boundary between one medium and another.

• A wave bends as it moves from one medium to another.

• Two waves overlap and combine.

Which of these waves would travel the farthest in air without losing too much information?

• Long-wave radio waves

• Short-wave radio waves

• Long-wave microwaves

• Short-wave microwaves

Answer explanation

Longer waves travel farther in air without losing information. Since radio waves are longer wavelength than microwaves, long-wave radio waves travel the farthest!

What type of wave would be able to carry more information faster?

• Long-wave radio

• Short-wave radio

• Long-wave microwaves

• Short-wave microwaves

Answer explanation

The higher frequency a wave is, the more information it can carry! Because short wavelengths = higher frequency, short-wave microwaves will carry more information than any of the other types in the list.

Can electromagnetic waves ever be dangerous to your health?

• Yes, and high frequency waves are the safest.

• Yes, and high frequency waves are the most dangerous.

• Yes, but frequency doesn't make a difference, only amplitude.

• No, electromagnetic waves are always safe.

Answer explanation

Higher energy EM waves can cause damage to cells or DNA, such as burns from UV light or cancer from exposure to X-rays. Both high frequency and high amplitude increase a wave's energy.

2 waves have the same amplitude, but opposite peaks and troughs. If they overlap, what will happen?

• They will cancel out, leaving no wave.

• They will make a wave with 2 times the amplitude.

• They will make a wave with 1/2 the amplitude.

• Both waves will exist in the same place.

Answer explanation

When two waves with the same frequency, same amplitude, and opposite phase (when one goes up the other goes down, for example) overlap, they create DESTRUCTIVE INTERFERENCE that cancels out both waves.