Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Waves
356 practice questions
Topics covered
Practice questions
161–170 of 172 · Easy
Question 161
1 mark · Easy
Answer and see the solution →Sound waves cannot travel through a vacuum. Give a reason why.
Question 162
2 marks · Easy
Answer and see the solution →A microphone is connected to an oscilloscope showing a sound wave. The trace shows a high number of waves close together. What does this tell you about the pitch of the sound, and why?
Question 163
4 marks · Easy
Answer and see the solution →Light and sound are both types of waves used for communication in different ways.
(a)[2 marks]State whether light and sound waves are transverse or longitudinal. Give one example of how each is used in daily life.
(b)[2 marks]Sound is reflected off a flat wall and returns to a listener as an echo. Light is reflected from a mirror.
Question 164
4 marks · Easy
Answer and see the solution →A student uses a ray box and a rectangular glass block to investigate how light travels through glass and how sound travels through air.
(a)[2 marks]Draw and label a simple ray diagram to show the path of a ray of light entering and leaving a rectangular glass block. Mark the normal, angle of incidence and angle of refraction.
(b)[2 marks]The student claps blocks of wood at a known distance from a wall. The time between clapping and hearing the echo is measured as 2.0 s, and the distance to the wall is 170 m. Calculate the speed of sound in air.
Question 165
4 marks · Easy
Answer and see the solution →Optical fibres use total internal reflection to transmit light signals, and sound waves can also be used in medicine.
(a)[2 marks]Explain how total internal reflection allows light to travel through an optical fibre without escaping.
(b)[2 marks]Doctors use optical fibres in endoscopes to see inside the body. State one reason why this is better than traditional surgery. Give one way sound is used in medicine.
Question 166
4 marks · Easy
Answer and see the solution →A student studies wave properties using a sound wave and a light wave.
(a)[2 marks]The student sets up a sound wave with a frequency of 100 Hz and speed 340 m/s. Calculate its wavelength.
(b)[2 marks]On an oscilloscope, the student sees two traces: - Trace A has high frequency and large amplitude. - Trace B has low frequency and small amplitude. Explain the difference in pitch and loudness between the two traces.
Question 167
4 marks · Easy
Answer and see the solution →Look at the diagram below showing a ray of light travelling from air into a glass block at 30° to the normal.
Ray of light entering glass at 30° to normal. (a)[1 mark]State the meaning of 'refraction'.
(b)[1 mark]Draw an arrow on the diagram to show the path of the refracted ray inside the glass block, bending towards the normal.
(c)[2 marks]Explain why the refracted ray bends towards the normal.
Question 168
4 marks · Easy
Answer and see the solution →A student investigates water waves in a ripple tank and observes the behaviour of a ray of light travelling from air into glass.
(a)[2 marks]Describe what is meant by the amplitude and wavelength of a wave.
(b)[1 mark]State what happens to the speed of a ray of light as it passes from air into glass.
(c)[1 mark]Give one unit, other than the metre, used for measuring waves.
Question 169
4 marks · Easy
Answer and see the solution →A sound wave travels through air at a speed of 340 m/s.
(a)[2 marks]If the frequency of the sound wave is 680 Hz, calculate its wavelength.
(b)[1 mark]Write down the equation you used for this calculation.
(c)[1 mark]Give one feature of a sound wave you can see displayed on an oscilloscope.
Question 170
4 marks · Easy
Answer and see the solution →A ray of light passes from air into water at an angle of incidence of 35°. The angle of refraction inside the water is measured as 22°.
(a)[2 marks]Calculate the refractive index of water. Show your working clearly.
(b)[1 mark]Write down the equation relating angle of incidence and angle of refraction to refractive index.
(c)[1 mark]Explain, in terms of wave speed, why refraction occurs when light passes from air into water.