Question 1

What is a wave?

Accepted Answer

A wave is a disturbance that transfers energy from one place to another without transferring matter.

Question 2

What is the difference between transverse and longitudinal waves?

Accepted Answer

In transverse waves, particles move perpendicular to wave direction; in longitudinal waves, particles move parallel to wave direction.

Question 3

What is wavelength?

Accepted Answer

Wavelength is the distance between two consecutive crests (or troughs) of a wave, measured in meters.

Question 4

What is frequency?

Accepted Answer

Frequency is the number of complete wave cycles that pass a point per second, measured in hertz (Hz).

Question 5

What is the relationship between frequency and wavelength?

Accepted Answer

Frequency and wavelength are inversely related: as frequency increases, wavelength decreases (wave speed = frequency × wavelength).

Question 6

What is amplitude and what does it represent?

Accepted Answer

Amplitude is the maximum displacement of a wave from its rest position; it represents the energy of the wave.

Question 7

What is the wave speed formula?

Accepted Answer

Wave speed (v) = frequency (f) × wavelength (λ). For example, a wave with frequency 5 Hz and wavelength 2 m travels at 10 m/s.

Question 8

What is the period of a wave?

Accepted Answer

The period (T) is the time it takes for one complete wave cycle to pass a point, measured in seconds. Period = 1 ÷ frequency.

Question 9

A wave has a frequency of 10 Hz and a wavelength of 3 m. What is its speed?

Accepted Answer

v = f × λ = 10 × 3 = 30 m/s.

Question 10

What is reflection?

Accepted Answer

Reflection occurs when a wave bounces off a surface and changes direction. The angle of incidence equals the angle of reflection.

Question 11

What is refraction?

Accepted Answer

Refraction is the bending of a wave as it passes from one medium into another with a different speed (e.g., light bending when it enters water from air).

Question 12

What is diffraction?

Accepted Answer

Diffraction is the bending and spreading of waves around obstacles or through openings. Diffraction is most noticeable when the opening is similar in size to the wavelength.

Question 13

What is wave interference?

Accepted Answer

Interference occurs when two waves overlap. Constructive interference produces a larger amplitude (waves add together); destructive interference reduces amplitude (waves cancel each other out).

Question 14

What is the Doppler effect?

Accepted Answer

The Doppler effect is the change in observed frequency (pitch or color) of a wave when the source or observer is moving. A moving source creates compressed waves ahead (higher frequency) and stretched waves behind (lower frequency).

Question 15

How does sound travel, and what type of wave is it?

Accepted Answer

Sound is a longitudinal mechanical wave that travels by compressing and expanding the medium (air, water, or solids). It cannot travel through a vacuum.

Question 16

How does the speed of sound vary in different media?

Accepted Answer

Sound travels faster in denser/stiffer media: fastest in solids, then liquids, then gases. Sound travels at ~343 m/s in air but ~1,480 m/s in water.

Question 17

What is the electromagnetic spectrum?

Accepted Answer

The electromagnetic spectrum is the range of all electromagnetic waves ordered by frequency/wavelength: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

Question 18

How is the pitch of a sound related to frequency?

Accepted Answer

Higher frequency sound waves produce higher pitch; lower frequency produces lower pitch. Humans can hear frequencies between approximately 20 Hz and 20,000 Hz.

Question 19

A sound wave has a frequency of 440 Hz (musical note A). If the speed of sound is 340 m/s, what is its wavelength?

Accepted Answer

λ = v ÷ f = 340 ÷ 440 ≈ 0.77 meters.

Question 20

Why does light bend when it passes from air into glass?

Accepted Answer

Light slows down when it enters a denser medium like glass. This change in speed causes the wave to bend (refract) at the boundary. The greater the speed change, the more bending occurs.

Question 21

A boat on the ocean creates waves. Explain why a floating buoy bobs up and down but does not move forward with the waves.

Accepted Answer

Waves transfer energy, not matter. The water particles (and the buoy) move in a circular path locally — up, forward, down, backward — returning to their original position. The wave energy moves forward, but the water itself does not.

Wave Properties Answer Key

Prior Knowledge Questions

Activity A – Wave Measurements

Activity B – Wave Interactions

Activity C – Sound and Light Waves

Assessment Questions

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