Pearson Edexcel International GCSE (9–1) · PHYSICS · Chapter
Light and Sound
70 practice questions
Topics covered
Practice questions
21–30 of 34 · Easy
Question 21
3 marks · Easy
Answer and see the solution →An engineer uses optical fibres to inspect the inside of a jet engine.
(a)[2 marks]State two reasons why using an optical fibre is useful in this situation.
(b)[1 mark]Explain how light travels from the entrance to the exit of the fibre.
Question 22
1 mark · Easy
Answer and check →Which statement best describes how light travels along an optical fibre?
- A.Light is refracted at the core–cladding boundary.
- B.Light is totally internally reflected at the core–cladding boundary.
- C.Light is absorbed by the core then re-emitted.
- D.Light bounces off the fibre's outer surface due to diffraction.
Question 23
2 marks · Easy
Answer and see the solution →State two different applications for optical fibres. For each, give a reason why optical fibres are a suitable choice.
Question 24
2 marks · Easy
Answer and see the solution →The table shows the refractive indices for different parts of an optical fibre:
Part of fibre Refractive index Core 1.52 Cladding 1.48 State which part ensures total internal reflection occurs, and explain your answer.
Question 25
1 mark · Easy
Answer and see the solution →What type of wave are sound waves in air (longitudinal or transverse)?
Question 26
1 mark · Easy
Answer and check →Which of the following instruments can be used to see the shape of a sound wave?
- A.Oscilloscope
- B.Thermometer
- C.Barometer
- D.Stopwatch
Question 27
2 marks · Easy
Answer and see the solution →The speed of sound in air is 340 m/s. Calculate how long it takes a sound wave to travel 170 m. Give your answer in seconds.
Question 28
2 marks · Easy
Answer and see the solution →A sound wave is displayed on an oscilloscope screen. The time for one complete wave (time period) on the screen is 0.01 s. Calculate the frequency of the sound wave. State the correct unit.
Question 29
1 mark · Easy
Answer and see the solution →Sound waves cannot travel through a vacuum. Give a reason why.
Question 30
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?