Introduction to Fibre Optics and Lasers: JAMB Physics Questions, Answers & Notes

What Introduction to Fibre Optics and Lasers covers in the JAMB Physics syllabus

An optical fibre is a very thin, pure glass strand that carries information as pulses of light, kept inside by total internal reflection (the incidence angle exceeds the critical angle, aided by low-index cladding around the higher-index core). Fibres carry huge amounts of data over long distances with low loss and immunity to electrical interference — ideal for telecommunications and the internet. A LASER (Light Amplification by Stimulated Emission of Radiation) produces monochromatic, coherent, narrow, intense light, used in surgery, CD/DVD players, cutting and welding, holograms and communications. Never look directly into a laser beam.

For Introduction to Fibre Optics and Lasers, JAMB expects you to be able to:

• Explain how optical fibres transmit light by total internal reflection
• State the advantages and uses of optical fibres
• Describe the properties, uses and safety of lasers

Key facts & revision notes: Introduction to Fibre Optics and Lasers

These are the recurring points our Introduction to Fibre Optics and Lasers questions test — revise them until each feels automatic, then practise the questions above to lock them in.

• Optical fibres carry information as pulses of light.
• Light stays inside an optical fibre by total internal reflection along its length.
• Total internal reflection needs the angle of incidence to exceed the critical angle.
• Optical fibres carry huge amounts of data with low loss and immunity to electrical interference.
• LASER = Light Amplification by Stimulated Emission of Radiation.
• Laser light is monochromatic (single colour/wavelength), coherent and forms a narrow, intense beam.
• Optical fibres are used in telecommunications, the internet and cable networks.
• Lasers are used in precise surgery, including eye surgery, often with little bleeding.
• Optical fibres are made of very pure, thin glass (or sometimes plastic).
• Coherent means the light waves are in phase (in step) with each other.
• CD/DVD players use a laser beam to read data pits on the disc.
• An optical fibre is extremely thin, comparable to a human hair.
• High-energy laser beams are used to cut, drill and weld materials with precision.
• Optical fibres have low attenuation, so signals travel far with little loss.
• Because of its high frequency, laser light offers very high bandwidth for carrying information.
• The core is the central part that carries the light; the cladding around it enables total internal reflection.
• The cladding has a lower refractive index than the core, allowing total internal reflection at the boundary.
• Holograms are three-dimensional images produced using coherent laser light.
• Because they carry light rather than electric current, optical fibres are not affected by electrical interference.
• Never look directly into a laser beam; it can damage the eyes.
• Protective goggles are used where needed.
• A laser or LED transmitter turns the electrical signal into light.
• A photodiode detects the light and produces an electrical signal.
• The lower-index cladding allows total internal reflection to trap the light.

Worked examples

Three Introduction to Fibre Optics and Lasers questions with the answer and a short explanation, so you can see how the topic is set before you practise the full set.

How Introduction to Fibre Optics and Lasers is tested in JAMB Physics

Our Introduction to Fibre Optics and Lasers bank holds 40 questions (2 easy, 25 medium, 13 hard). JAMB Physics typically returns to Introduction to Fibre Optics and Lasers year after year, so steady practice on this topic is high-value revision. Questions are multiple-choice with four options, and at UTME pace you get roughly 40 seconds each — which is why timed practice matters.

How to answer Introduction to Fibre Optics and Lasers questions

Work the stem first and predict the answer before you look at the options; then eliminate the ones that contradict the key facts above. Watch for “which is not…”, “all of the above” and “except” style stems, which are where rushed candidates lose easy marks on Introduction to Fibre Optics and Lasers. If a calculation or a precise definition is involved, work it from first principles rather than guessing from a half-remembered rule. When two options look right, re-read the stem for the qualifier that separates them — JAMB rarely repeats an option by accident. If you are still unsure, eliminate the two weakest choices to lift your odds, flag the question, and move on; never burn a full minute on one Physics item when the exam gives you about forty seconds each. Then come back to flagged questions with whatever time remains. The single most reliable way to get faster at Introduction to Fibre Optics and Lasers is repeated timed practice, so use the button above until the recurring patterns feel automatic.

Common mistakes to avoid in Introduction to Fibre Optics and Lasers

The errors that cost marks on Introduction to Fibre Optics and Lasers are usually careless rather than conceptual: misreading a negative stem, confusing two similar terms, or rushing a definition you actually know. Candidates also over-rely on “expo” and last-minute cramming instead of understanding the topic — which fails the moment JAMB rephrases a familiar idea. Treat every option as a claim to be checked against the facts above, keep your working tidy for any calculation, and don’t change a considered answer on a hunch. Above all, revise Introduction to Fibre Optics and Lasers actively by answering questions, not just by re-reading notes — recall under time is what the exam rewards.

Frequently asked questions

Is Introduction to Fibre Optics and Lasers part of the JAMB Physics syllabus?

Yes. Introduction to Fibre Optics and Lasers is a recognised topic in the JAMB Physics syllabus, covering explain how optical fibres transmit light by total internal reflection. You should be able to recall its key facts and apply them to multiple-choice questions.

How many Introduction to Fibre Optics and Lasers questions can I practise on Belmadeng?

There are 40 original, JAMB-standard Introduction to Fibre Optics and Lasers questions in our free bank, each with the correct answer and a worked explanation. You can practise them untimed or as a timed test.

What are the most important points to know about Introduction to Fibre Optics and Lasers?

An optical fibre is a very thin, pure glass strand that carries information as pulses of light, kept inside by total internal reflection (the incidence angle exceeds the critical angle, aided by low-index cladding around the higher-index core). Fibres carry huge amounts of data over long distances w…

How do I answer Introduction to Fibre Optics and Lasers questions quickly in JAMB?

Read the stem carefully, eliminate clearly wrong options, and match the remaining choices to the key facts for Introduction to Fibre Optics and Lasers. Practising timed Introduction to Fibre Optics and Lasers questions builds the speed you need for UTME's pace of about 40 seconds per question.

Are these JAMB Physics Introduction to Fibre Optics and Lasers questions past questions or original?

They are original questions written to JAMB (UTME) standard and mapped to the official syllabus — not reproduced past papers. This keeps them legal to use freely while closely mirroring how the real exam tests the topic.

Where can I practise Introduction to Fibre Optics and Lasers questions free without signing up?

Right here — tap “Start Introduction to Fibre Optics and Lasers practice” on this page to begin instantly. Belmadeng's CBT practice is completely free and needs no sign-up, download or subscription.

About these questions: original, JAMB-standard items written from the official UTME Physics syllabus (last reviewed 2026-09-18). Belmadeng is an independent study platform and is not affiliated with JAMB. Spotted an error? Use the report link.