NEET UG · Physics · Ray Optics and Optical Instruments
Prisms, Dispersion and Optical Instruments: NEET previous year questions
8 questions in ten years of NEET, in 7 of 10 papers. Pattern: Every year. Here is how it is asked and which ideas come back.
- Asked in 10 years
- 8
- about 0.8 per paper
- Years asked
- 7/10
- last asked 2025
- Weighted estimate
- 0.6
- model; history: 0.8 a paper on average, typically 0–1
Key findings
- 01
Asked in 7 of 10 papers, 8 questions in all: #110 of 204 topics by ten-year total. It comes back every 1.3 years on average. Last asked in 2025.
- 02
50% of its questions since 2018 tested an idea never asked before; none repeated an idea from the year before.
- 03
The most repeated idea is Astronomical Telescope, asked 3 times (2018, 2021, 2024), usually as “design choice for astronomical telescope objective”.
- 04
NEET has asked 0 of the 6 ideas in this topic; 0 have never been asked, directly or indirectly.
- 05
Mostly asked as numerical (50%); 25% easy, 0% hard.
Questions per year
- Up to 2023
- 0.8
- per paper
- Since 2024
- 0.6
- -0.2
- Usual gap
- 1.3 yrs
- between papers asking it
- Swing
- ±0.6
- questions, year to year
How it is asked
Difficulty, format and skill
Across all 8 questions on Prisms, Dispersion and Optical Instruments since 2017.
Difficulty
QUESTIONS- Easy2 · 25%
- Medium6 · 75%
- Hard0 · 0%
Format
SHARE- Numerical · 4 Q50%
- One-line MCQ · 4 Q50%
Skill tested
SHARE- Calculation · 3 Q38%
- Concept · 2 Q25%
- Application · 2 Q25%
- Recall · 1 Q13%
Repeats
New idea, or one asked before?
Each column is a paper. Blue questions tested an idea NEET had not asked before; navy ones went back to an idea from an earlier paper. 2017 is the first paper, so everything in it counts as new.
- Idea asked for the first time
- Idea asked in an earlier paper
Coverage of the topic
NEET has asked 0 of the 6 ideas in this topic. 0 have never been asked yet.
- Asked directly0 · 0%
- Touched inside another question6 · 100%
- Never asked0 · 0%
Ideas come from Lumi’s syllabus map of NCERT. A never-asked idea is not a safe skip: most new questions come from exactly these.
Drill down
Idea, year, question
Every idea NEET tested in this topic, with its ten papers. Open one to read the questions.
- Repeated3 · 38%
- 2024 · Q40A small telescope has an objective of focal length 140 cm and an eye piece of focal length 5.0 cm. The magnifying power of telescope for…
easyNumerical
- 2021 · Q15A lens of large focal length and large aperture is best suited as an objective of an astronomical telescope since :
mediumOne-line MCQ
- 2018 · Q10An astronomical refracting telescope will have large angular magnification and high angular resolution, when it has an objective lens of
mediumOne-line MCQNew idea
- 2024 · Q40
- Repeated2 · 25%
- 1 · 13%
- 1 · 13%
- 1 · 13%
Squares are the ten papers, 2017 to 2026; darker means more questions. Share is of the level above.
Ideas
Every idea inside this topic
5 different ideas were tested; 2 came more than once.
- Astronomical Telescope3×
design choice for astronomical telescope objective
One-line MCQ · 6% next - Thin Prisms and Dispersion2×
small-angle prism emergence condition
Numerical · 4% next - Compound Microscope1×
numerical
Numerical · 6% next - Rainbow Formation1×
pick wrong statement on rainbow
One-line MCQ · 4% next - Rotation of a Plane Mirror1×
angle of mirror rotation from spot shift
One-line MCQ · 4% next
Chance next is the historical rate at which an idea with this record came back in the following paper. It is low for every idea, which is why learning the topic beats memorising past questions. All repeated ideas
Every question
Prisms, Dispersion and Optical Instruments questions, year by year
The opening words of each question as it appeared in the official paper, with the idea it tested.
NEET 20251 question
- Q2A microscope has an objective of focal length 2 cm, eyepiece of focal length 4 cm and the tube length of 40 cm. If the distance of…
Idea: Compound Microscope
New ideaMediumNumerical
NEET 20241 question
- Q40A small telescope has an objective of focal length 140 cm and an eye piece of focal length 5.0 cm. The magnifying power of telescope for…
Idea: Astronomical Telescope
EasyNumerical
NEET 20211 question
- Q15A lens of large focal length and large aperture is best suited as an objective of an astronomical telescope since :
Idea: Astronomical Telescope
MediumOne-line MCQ
NEET 20201 question
- Q140A ray is incident at an angle of incidence on one surface of a small angle prism (with angle of prism A) and emerges normally from the…
Idea: Thin Prisms and Dispersion
MediumNumerical
NEET 20191 question
- Q15Pick the wrong answer in the context with rainbow.
Idea: Rainbow Formation
New ideaMediumOne-line MCQ
NEET 20181 question
- Q10An astronomical refracting telescope will have large angular magnification and high angular resolution, when it has an objective lens of
Idea: Astronomical Telescope
New ideaMediumOne-line MCQ
NEET 20172 questions
- Q42A beam of light from a source L is incident normally on a plane mirror fixed at a certain distance from the source. The beam is…
Idea: Rotation of a Plane Mirror
EasyOne-line MCQ - Q44A thin prism having refracting angle 10° is made of glass of refractive index 1.42. This prism is combined with another thin prism of…
Idea: Thin Prisms and Dispersion
MediumNumerical
Questions from the official NEET UG papers published by NTA (CBSE before 2019). Topic and idea tags, counts and notes are Lumi’s.