Skip to content
Book Free Demo

Light: Reflection, Refraction, Lenses and the Human Eye – GK Quiz with Answers – Level 3

Hard GK questions on light: Snell's law, lens power in dioptres, eye defects and their corrections, scattering of sunlight and how the eye forms an image.

Start Test

Choose Normal practice or a Simulated test.

Questions, answer key and solutions.

Questions
50
Duration
35 min
Marks
50

Negative marking

Attempts
100
Access
Free
Share test:

Normal practice, or a Simulated test

Both use the same questions. Normal practice is untimed and needs no account: choose an option and the answer and solution appear at once. The Simulated test is the real computer-based format, with one 35-minute clock, a question palette and full screen, and your score, the key and the solutions arrive when you submit.

Open Normal practiceTake the Simulated test
How the two modes differ
No account needed

Normal

Untimed

Every question on one page, loading as you scroll. Choose an option and see straight away whether it was right.

  • No timer. Nothing to start and nothing to submit. Stop whenever you like.
  • Answered as you choose. Tap an option and it is marked at once, with the correct answer shown.
  • Solutions in place. The explanation, and the video where one has been added, sit under the question.
  • Open to guests. Normal practice needs no sign-in.
Real exam conditions

Simulated

Timed CBT

The computer-based test format: one clock, a question palette, and a score the moment you submit.

  • A clock that does not pause. 35 minutes from the moment you begin, and the paper is submitted for you when it reaches zero.
  • Question palette. Answered, not answered and marked for review, section by section, as the real interface has it.
  • Full screen, proctored. The test takes over the screen; leaving it three times submits the paper.
  • Answers hidden until you submit. The key, the explanations and your score all arrive together at the end.

About this test

Light GK Quiz Level 3: Reflection, Refraction, Lenses and Human Eye

This Level 3 Aptitude360 quiz is for General Awareness aspirants in the final stage of physics revision, and it tests light: reflection, refraction, lenses and the human eye. Its statement-based, match-the-list and sequencing questions cover mirrors, lens power, vision defects and atmospheric optics. Every question has a written explanation.

Topics covered in this light and optics GK set

  • Laws of reflection, plane mirror images and lateral inversion
  • Spherical mirrors: focal length, radius of curvature and uses such as shaving mirrors, rear-view mirrors and solar furnaces
  • Refraction, Snell's law and the high refractive index of diamond
  • Concave and convex lenses, lens power in dioptres and the sign convention for power
  • Parts of the human eye and the path light takes from the cornea to the retina
  • Myopia, hypermetropia, presbyopia and cataract, with their corrections
  • Dispersion, the rainbow, scattering, the Tyndall effect and twinkling of stars

Key concepts to revise on light and vision

  • Which mirror or lens forms real, virtual, erect or inverted images
  • Why a convex lens is converging and a concave lens is diverging, and how this shows in the sign of power
  • The roles of the iris, pupil, ciliary muscles and optic nerve
  • Atmospheric refraction effects such as advanced sunrise, delayed sunset and twinkling stars
  • Order of colours in the spectrum and which colour bends or scatters most

Revision tips for hard optics GK questions

  • Make a table of each eye defect with its cause and the lens that corrects it
  • Practise converting focal length in metres into power, and remember that a shorter absolute focal length means a greater absolute power
  • Link each everyday observation, like the blue sky or the red sunset, to one optical cause

Who should take this Level 3 light quiz

This set suits aspirants who have finished the easier levels and want to test General Awareness physics with tricky, multi-statement questions.

FAQs about Light: Reflection, Refraction, Lenses and the Human Eye – GK Quiz with Answers – Level 3

Why do stars twinkle more than planets?
Stars are so far away that they act as point sources, so atmospheric refraction makes their light flicker noticeably. Planets are closer and appear as extended sources, so the flickering largely averages out. They usually twinkle much less than stars, though they can twinkle, especially near the horizon.
Which lens is used to correct myopia?
Myopia, or short-sightedness, is corrected with a concave lens. Hypermetropia is corrected with a convex lens.
What is the power of a lens and its unit?
The power of a lens is the reciprocal of its focal length measured in metres. Its SI unit is the dioptre, and a lens with a focal length of one metre has a power of one dioptre.
Why does the sky appear blue?
Very small particles in the air scatter shorter wavelengths such as blue much more than longer wavelengths such as red. This scattered blue light reaches our eyes from all directions.

Test structure

How the paper is split, and how long each part runs. A section you have finished cannot be returned to.

SectionQuestionsTime
Light: Reflection, Refraction, Lenses and the Human Eye GK Level 35035 min

Marking & rules

Total marks
50 across 50 questions.
Negative marking
A wrong answer costs marks. Leaving a question unanswered costs nothing.
Attempts
100 in total. An attempt is spent the moment you begin one.

What you get when you submit

The analysis is ready the moment you submit the paper.

Score and accuracy

Marks, percentage, right, wrong and skipped, and the time you took.

Section by section

The same figures for each section, so a weak one cannot hide in an average.

The full answer key

Every question with your answer, the right one, the working, and the video where there is one.

Where you stand

Your score against the spread of everyone else who has sat this test.

Recommended courses for CAT & OMET

All CAT & OMET courses
Chat with an academic counsellor on WhatsApp