General Properties of Waves (Cambridge (CIE) IGCSE Physics): Exam Questions

Fig. 8.1 represents a travelling wave at an instant in time.

(i) Determine the amplitude of the wave.

amplitude = .................................................. cm [1]

(ii) Determine the wavelength of the wave.

wavelength = .................................................. cm [2]

(iii) It takes 2.0 s for a source to emit the wave shown in Fig. 8.1.

  Calculate the frequency of the wave. 

frequency = .................................................. Hz [2]

Fig. 8.2 shows the main regions of the electromagnetic spectrum.

(i) Two of the regions are not labelled.

Add the correct label to each of the unlabelled regions by writing in each box.

[2]

(ii) Describe one use of γ-rays.

[1]

Fig. 6.1 shows crests of a water wave moving from left to right in a harbour.

(i) On Fig. 6.1, draw three more crests to the right of point A.

[2]

(ii) State the name of the wave process that occurs as the wave passes point A.

[1]

Fig. 6.2 shows the crests of another wave moving from left to right in a different part of the harbour. This wave moves from deep water to shallow water.

(i) On Fig. 6.2, draw an arrow to show the direction of movement of the wave after it has passed into the shallow water.

[1]

(ii) State the name of the process that occurs as the wave passes into the shallow water.

[1]

(iii) Complete Table 6.1 to state whether each of the properties of the wave increases, decreases or stays the same as the wave passes into the shallow water.

[3]

Fig. 6.1 represents a transverse wave drawn full size. Point X represents a point on the wave.

(i) On Fig. 6.1, mark clearly the directions in which point X moves.

[1]

(ii) Use Fig. 6.1 to measure the wavelength of the wave.

wavelength = ................................................... cm [1]

(iii) The frequency of the wave is increased. Describe how the wave pattern in Fig. 6.1 would be different.

[1]

(i) Place a tick in a box next to any transverse wave.

  light

 sound

  radio

 [1]

(ii) State a type of wave that cannot travel in a vacuum.

[1]

Sound is a longitudinal wave.

Sketch a representation of a longitudinal wave. On your sketch

  • indicate and label a distance to show the wavelength, • mark and label the centre of one compression, • mark and label the centre of one rarefaction.

A longitudinal wave passes from one medium into another medium. The speed of the wave is slower in the second medium.

State what happens to

(i) the frequency of the wave,

[1]

(ii) the wavelength of the wave.

[1]

State a typical value for the speed of sound in air.

A ray of light travelling in air strikes a glass block at an angle of 30° to the normal. The light slows down as it enters the glass block.

State and explain, in terms of wavefronts, what happens to the light.

Fig. 7.1 shows a floating plastic ball attached by a long rope to a weight on the bottom of a lake. 

A water wave on the surface of the lake causes the ball to move vertically up and down.

On Fig. 7.1, show the wavelength of the wave. Label the distance W

Determine the amplitude of the wave. 

amplitude = ....................................................  cm

The ball reaches its maximum height 40 times in 60 seconds. Calculate the frequency of the wave.

frequency = ..................................................... Hz

Explain how the motion of the ball shows that the water wave is transverse. 

 State another example of a transverse wave.

Fig. 8.2 represents some wavefronts approaching a barrier with a narrow gap.

On Fig. 8.2, draw three wavefronts that have passed through the gap.

Fig. 7.1 shows the displacement of particles in a water wave

Using the information in Fig. 7.1, determine: 

(i) the wavelength of the wave 

wavelength = ................................................... cm [1] 

(ii) the amplitude of the wave. 

amplitude = ................................................... cm [1]

A student observes waves on the surface of water in a tank. The waves all have the same wavelength.

The student measures the wavelength of the waves by measuring the distance between one peak and the next peak.

Describe a more accurate method for determining the wavelength.

The wavelength of the waves is 4.0 cm and their frequency is 6.0 Hz.

Calculate the wave speed.

wave speed = ................................................ cm / s

 Fig. 6.1 shows water waves in the tank travelling from deep water to shallow water.

State and explain what happens to the waves as they move from deep water to shallow water.

name of effect ..........................................................................................

explanation ...............................................................................................

Describe a method of using water waves to demonstrate refraction.

Fig. 5.1 shows crests of a wave approaching a barrier where the wave is reflected.

On Fig. 5.1, draw three crests of the reflected wave.

The wave has a wavelength of 36 cm and a speed of 1.2 m/s.

  Calculate the frequency of the wave.

frequency = .........................................................

Complete the following sentences.

  An echo is the name for a reflected .................................................................. wave.

  The waves that form an echo are a type of longitudinal wave. Longitudinal waves are made up of .................................................................. and rarefactions.

Extended tier only

Fig. 6.1 shows wavefronts approaching a gap in a barrier.

(i) On Fig. 6.1, draw three wavefronts to the right of the barrier.

[2]

(ii) Fig. 6.2 shows the gap in the barrier increased to five times the gap in Fig. 6.1.

On Fig. 6.2, draw three wavefronts to the right of the barrier.

[2]

Describe, with a labelled diagram, an experiment using water waves that shows the reflection of wavefronts that occur at a straight barrier.

Green light of frequency 5.7 × 10¹⁴ Hz is travelling in air at a speed of 3.0 × 10⁸ m/s. The light is incident on the surface of a transparent solid.

Fig. 6.1 shows the wavefronts and the direction of travel of the light in the air.

The light travels more slowly in the transparent solid.

Explain, in terms of the wavefronts, why the light changes direction as it enters the solid. You may draw on Fig. 6.1 as part of your answer.

Extended tier only

The refractive index of the transparent solid is 1.3.

(i) The light is incident on the surface of the solid at an angle of incidence of 67°.

Calculate the angle of refraction of the light in the solid.

angle of refraction = ......................................................... [2]

(ii) Determine the wavelength of the green light in the transparent solid.

     wavelength = ......................................................... [4]

A group of students want to determine the speed of sound in air.

Describe a method they can use. State the measurements they need to make.