DP Physics Questionbank

Description

Nature of science:

Applied science: Advances in communication links using fibre optics have led to a global network of optical fibres that has transformed global communications by voice, video and data. (1.2)

Understandings:

• Structure of optic fibres
• Step-index fibres and graded-index fibres
• Total internal reflection and critical angle
• Waveguide and material dispersion in optic fibres
• Attenuation and the decibel (dB) scale

Applications and skills:

• Solving problems involving total internal reflection and critical angle in the context of fibre optics
• Describing how waveguide and material dispersion can lead to attenuation and how this can be accounted for
• Solving problems involving attenuation
• Describing the advantages of fibre optics over twisted pair and coaxial cables

Guidance:

• Quantitative descriptions of attenuation are required and include attenuation per unit length
• The term waveguide dispersion will be used in examinations. Waveguide dispersion is sometimes known as modal dispersion.

Data booklet reference:

International-mindedness:

• The under-sea optic fibres are a vital part of the communication between continents

Utilization:

• Will a communication limit be reached as we cannot move information faster than the speed of light?

Aims:

• Aim 1: this is a global technology that embraces and drives increases in communication speeds
• Aim 9: the dispersion effects illustrate the inherent limitations that can be part of a technology

Directly related questions

• 18M.3.SL.TZ1.9c.iii: Explain how the use of a graded-index fibre will improve the performance of this fibre optic system.
• 18M.3.SL.TZ1.9c.ii: Calculate the power of the output signal after the signal has travelled a distance of 3.40 km in...
• 18M.3.SL.TZ1.9c.i: Draw on the axes an output signal to illustrate the effect of waveguide dispersion.
• 18M.3.SL.TZ1.9b: The use of optical fibres has led to a revolution in communications across the globe. Outline two...
• 18M.3.SL.TZ1.9a: Calculate the critical angle at the core−cladding boundary.
• 18M.3.SL.TZ2.10c: In many places clad optic fibres are replacing copper cables. State one example of how fibre...
• 18M.3.SL.TZ2.10b.iii: The graph shows the variation with wavelength of the refractive index of the glass from which the...
• 18M.3.SL.TZ2.10b.ii: An amplifier can increase the power of the signal by 12 dB. Determine the minimum number of...
• 18M.3.SL.TZ2.10b.i: Calculate the maximum attenuation allowed for the signal.
• 18M.3.SL.TZ2.10a: An optic fibre of refractive index 1.4475 is surrounded by air. The critical angle for the core –...
• 17N.3.HL.TZ0.15b: Outline how the combination of core and cladding reduces the overall dispersion in the optic fibres.
• 17N.3.HL.TZ0.15a: Calculate the maximum angle β for light to travel through the fibre. Refractive index of core   ...
• 17M.3.SL.TZ2.10b.ii: The length of the optic fibre is 5.1 km. The input power of the signal is 320 mW. The output...
• 17M.3.SL.TZ2.10b.i: Identify the features of the output signal that indicate the presence of attenuation and...
• 17M.3.SL.TZ2.10a: The diagram shows a ray of light in air that enters the core of an optic fibre. The ray makes...
• 17M.3.SL.TZ1.8c: State and explain why it is an advantage for the core of an optic fibre to be extremely thin.
• 17M.3.SL.TZ1.8b: A signal with an input power of 15 mW is transmitted along an optic fibre which has an...
• 17M.3.SL.TZ1.8a.ii: Suggest why infrared radiation rather than visible light is used in these transmissions.
• 17M.3.SL.TZ1.8a.i: State two advantages of optic fibres over coaxial cables for these transmissions.
• 16N.3.SL.TZ0.14b: Explain why graded-index fibres help reduce waveguide dispersion.
• 16N.3.SL.TZ0.14a: State the main physical difference between step-index and graded-index fibres.
• 16M.3.SL.TZ0.11b: Explain how the graded-index optic fibre reduces waveguide dispersion.
• 16M.3.SL.TZ0.11a: Draw the path of the ray as it travels through the graded-index optic fibre.
• 15M.3.SL.TZ2.18b: In an optic fibre the refractive index of the core is 1.62. The refractive index for the cladding...
• 15M.3.SL.TZ2.18a: Explain, with reference to the critical angle, what is meant by total internal reflection
• 15M.3.SL.TZ2.18c: State one effect of dispersion on a pulse that has travelled along an optic fibre.
• 14M.3.SL.TZ1.19a: Electromagnetic waves propagating in a medium suffer dispersion. Describe what is meant by...
• 14N.3.SL.TZ0.19b: The input power to the fibre is 150 mW. The attenuation per unit length of the glass fibre is...
• 14N.3.SL.TZ0.19a.i: Calculate the critical angle for this optic fibre.
• 14N.3.SL.TZ0.19a.ii: The diagram shows a straight optic fibre. Sketch the passage of a ray of light through the fibre.
• 14M.3.SL.TZ2.17b: (i)     Determine, using the data, the greatest distance the signal can travel before it must be...
• 14M.3.SL.TZ2.17a: State what is meant by attenuation.
• 13M.3.SL.TZ1.19a: Calculate the greatest angle of incidence θ that can be used with this fibre.
• 13M.3.SL.TZ1.19b: Sketch the path of the light in the core on the diagram above.
• 12N.3.SL.TZ0.19a: State one advantage of the use of an optic fibre rather than a coaxial cable for the transmission...
• 12N.3.SL.TZ0.19c: A signal is fed into an optic fibre of length L. The noise power at the receiver is Pnoise=4.2...
• 11N.3.SL.TZ0.14d: Digital information that is transmitted along optic fibres is often subject to dispersion due to...
• 12N.3.SL.TZ0.19b: Suggest why, in transmitting information in an optic fibre, infrared electromagnetic radiation...
• 12M.3.HL.TZ2.5b: The input power to a single optic fibre X is 25 mW. The signal needs to be amplified when the...
• 10N.3.SL.TZ0.F2a: State what is meant by material dispersion.
• 10N.3.SL.TZ0.F2c: (i)     The signal shown below is fed into a monomode optical fibre. On the diagram above,...