Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Waves
356 practice questions
Topics covered
Practice questions
311–320 of 356
Question 311
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 312
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 313
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 314
2 marks · Normal
Answer and see the solution →Describe the main structure of an optical fibre. Name the two main parts and their roles.
Question 315
1 mark · Normal
Answer and check →Which of the following is a correct statement about total internal reflection in an optical fibre?
- A.It can occur only when light travels from a region of lower to higher refractive index.
- B.It occurs whenever light enters an optical fibre, regardless of angle.
- C.It keeps light inside the core of the fibre if the angle is greater than the critical angle.
- D.It allows light to escape from the sides of the fibre easily.
Question 316
3 marks · Normal
Answer and see the solution →Explain how total internal reflection inside an optical fibre ensures that light follows the path of the fibre even if it bends.
Question 317
2 marks · Normal
Answer and see the solution →A telecommunications company wants to replace copper wires with optical fibres. Give two reasons, based on physics, why optical fibres are better for transmitting signals over long distances.
Question 318
4 marks · Normal
Answer and see the solution →The diagram below shows a simplified optical fibre.
Simplified cross-section of an optical fibre. (a)[1 mark]Label the core and cladding on the diagram.
(b)[2 marks]Draw a path to show how light travels along the optical fibre, reflecting from the core–cladding boundary.
(c)[1 mark]Explain why the light remains in the core as it travels.
Question 319
4 marks · Normal
Answer and see the solution →Read the passage: 'A bundle of optical fibres is used in a medical endoscope to allow a doctor to see inside a patient’s stomach.'
(a)[2 marks]Describe how the endoscope uses optical fibres to allow the doctor to see inside the body.
(b)[2 marks]State two reasons why using an endoscope made with optical fibres is an advantage for the patient, compared to traditional open surgery.
Question 320
2 marks · Normal
Answer and see the solution →State two different applications of optical fibres, other than medical endoscopes, and briefly describe how they work.