JEE (Advanced) · Physics, Class 11
Physical World and Measurement: JEE Advanced PYQ, 2007–2026
Physical World and Measurement (Physics, Class 11) has been asked 35 times in the 40 JEE (Advanced) papers from 2007–2026: about 0.9 questions a paper, 5% of all Physics questions. It is the 10th most-asked of 19 Physics chapters. The two 2026 papers had 2 from it. Last checked 28 October 2026.
Questions per year, both papers
Year by year.
| Year | Questions |
|---|---|
| 2007 | 2in 2 papers |
| 2008 | 1in 2 papers |
| 2009 | 0in 2 papers |
| 2010 | 2in 2 papers |
| 2011 | 2in 2 papers |
| 2012 | 1in 2 papers |
| 2013 | 2in 2 papers |
| 2014 | 1in 2 papers |
| 2015 | 3in 2 papers |
| 2016 | 2in 2 papers |
| 2017 | 1in 2 papers |
| 2018 | 4in 2 papers |
| 2019 | 1in 2 papers |
| 2020 | 2in 2 papers |
| 2021 | 1in 2 papers |
| 2022 | 1in 2 papers |
| 2023 | 2in 2 papers |
| 2024 | 2in 2 papers |
| 2025 | 3in 2 papers |
| 2026 | 2in 2 papers |
Each year has two papers, and the number of questions has fallen over time, so compare per paper and expect some drift.
Inside the chapter
Topics asked most.
- Dimensional analysis16
- Error analysis15
- Units and dimensions3
- Significant figures1
Try it
10 Physical World and Measurement questions to practise.
Our own questions, written in the JEE Advanced pattern and checked, each with an explanation. Pick an option to see the answer.
Q1 · Physics · Physical World and Measurement
A metal piece has a mass of 8.50 g and a volume of 3.2 cm³. Its density, reported with the correct number of significant figures, is:
Answer: (D)
For multiplication and division the result has as many significant figures as the least precise quantity. The mass 8.50 g has three significant figures and the volume 3.2 cm³ has two. The calculation gives 8.50 / 3.2 = 2.65625 g cm⁻³, which is rounded to two significant figures as 2.7 g cm⁻³.
Q2 · Physics · Physical World and Measurement
The radius R of the shock front of a strong explosion is assumed to depend only on the energy E released, the time t elapsed since the explosion, and the density ρ of the surrounding air, as R ∝ Eᵃ tᵇ ρᶜ. At the same instant t and in air of the same density, the energy released is increased 32 times. By what factor does R increase?
Answer: (C)
Write the dimensions as [L] = [M L² T⁻²]ᵃ [T]ᵇ [M L⁻³]ᶜ. Mass: a + c = 0. Length: 2a − 3c = 1. Time: −2a + b = 0. From the mass equation c = −a, so the length equation gives 2a + 3a = 1, hence a = 1/5, c = −1/5 and b = 2/5. So R ∝ E^(1/5) t^(2/5) ρ^(−1/5). With t and ρ fixed, R ∝ E^(1/5). Multiplying E by 32 multiplies R by 32^(1/5) = 2.
Q3 · Physics · Physical World and Measurement
The speed v of short surface ripples on a liquid is assumed to depend only on the surface tension S of the liquid (dimensions of force per unit length), the density ρ of the liquid, and the wavelength λ of the ripples. Using dimensional analysis, which expression for v is dimensionally consistent (the numerical constant is dimensionless)?
Answer: (B)
Write v = k Sᵃ ρᵇ λᶜ. The dimensions are [v] = L T⁻¹, [S] = M T⁻², [ρ] = M L⁻³ and [λ] = L. Equating powers of M gives a + b = 0. Equating powers of T gives −2a = −1, so a = 1/2 and b = −1/2. Equating powers of L gives −3b + c = 1, so 3/2 + c = 1 and c = −1/2. Hence v ∝ S^(1/2) ρ^(−1/2) λ^(−1/2) = √(S/(ρλ)).
Q4 · Physics · Physical World and Measurement
A vernier callipers has 10 vernier scale divisions equal to 9 main scale divisions, and 1 main scale division is 1 mm. With the jaws closed, the 5th vernier division coincides with a main scale division and the zero of the vernier lies to the right of the main scale zero. A wire is then placed between the jaws. The main scale reads 0.3 cm and the 8th vernier division coincides with a main scale division. Taking the error in the corrected diameter as one least count of the instrument, what is the percentage error in the cross-sectional area (A = πd²/4) of the wire?
Answer: (A)
Least count = 1 MSD − 1 VSD = 1 mm − 0.9 mm = 0.1 mm = 0.01 cm. The zero error is positive: 5 × 0.01 = +0.05 cm, so it is subtracted. The reading is 0.3 + 8 × 0.01 = 0.38 cm, and the corrected diameter is 0.38 − 0.05 = 0.33 cm. Since A ∝ d², ΔA/A = 2Δd/d = 2 × 0.01/0.33 ≈ 0.061, which is 6.1%.
Q5 · Physics · Physical World and Measurement
In SI, Coulomb's law is written F = q₁q₂ / (4πε₀r²). Taking the dimensional formula of electric charge as [A T], what is the dimensional formula of the permittivity of free space ε₀?
Answer: (A)
Rearrange Coulomb's law to ε₀ = q₁q₂/(4π F r²). The factor 4π is dimensionless. The charge has dimensions [A T], so q² has [A² T²]. The force has [M L T⁻²] and r² has [L²]. Therefore [ε₀] = [A² T²] / [M L³ T⁻²] = [M⁻¹ L⁻³ T⁴ A²].
Q6 · Physics · Physical World and Measurement
In a certain system of units the three base quantities are force [F], velocity [V] and time [T]. What is the dimensional formula of mass density (mass per unit volume) in this system?
Answer: (A)
Express mass and length in terms of the chosen base quantities. Force has dimensions M L T⁻², and since V = L/T this equals M V T⁻¹. So M = F T V⁻¹. Length is L = V T. Density is M L⁻³ = (F T V⁻¹)(V T)⁻³ = F V⁻⁴ T⁻². Check in SI: N · s⁻² · (m s⁻¹)⁻⁴ · s⁴ reduces to kg m⁻³, as expected.
Q7 · Physics · Physical World and Measurement
The van der Waals equation for one mole of a real gas is (P + a/V²)(V − b) = RT, where P is pressure, V is molar volume, T is temperature and R is the gas constant. What are the dimensions of the constant a?
Answer: (D)
Only quantities with the same dimensions can be added, so a/V² must have the dimensions of pressure P. Hence [a] = [P][V²] = (M L⁻¹ T⁻²)(L³)² = M L⁵ T⁻². Dividing by V² instead gives M L⁻⁷ T⁻². Using P alone gives M L⁻¹ T⁻². Using P·V gives M L² T⁻².
Q8 · Physics · Physical World and Measurement
The volume of liquid flowing per unit time (volume flow rate Q) through a long narrow horizontal pipe in steady flow is assumed to depend only on the pressure gradient along the pipe (pressure difference per unit length, ΔP/l), the internal radius r of the pipe, and the coefficient of viscosity η of the liquid. Using dimensional analysis, which expression for Q is dimensionally consistent (k is a dimensionless constant)?
Answer: (A)
Write Q = k (ΔP/l)^a r^b η^c. The dimensions are [Q] = L³T⁻¹, [ΔP/l] = (ML⁻¹T⁻²)/L = ML⁻²T⁻², [r] = L and [η] = ML⁻¹T⁻¹. Equating powers of M gives a + c = 0. Equating powers of T gives −2a − c = −1. Together these give a = 1 and c = −1. Equating powers of L gives −2a + b − c = 3, so −2 + b + 1 = 3 and b = 4. Hence Q ∝ (ΔP/l) r⁴/η. A common error is to use the dimensions of pressure for the gradient, which gives r³ instead of r⁴.
Q9 · Physics · Physical World and Measurement
A student records ten readings of the resistance of a wire. The readings scatter unpredictably about a central value because the room temperature fluctuates irregularly during the experiment. Which of the following describes this error and the effect of repeated measurements?
Answer: (C)
Errors that occur irregularly, with varying size and sign, because of unpredictable causes such as fluctuating temperature are random errors. Their effect can be reduced by averaging many readings, since deviations on either side of the true value tend to cancel. Systematic errors, such as an offset pointer or an instrument defect, shift all readings the same way and are not reduced by averaging. Gross errors are personal blunders, and least count error is set by the instrument's resolution.
Q10 · Physics · Physical World and Measurement
Four measurements are recorded, and in each the last written digit is uncertain by ±1 unit. Which measurement has the SMALLEST fractional (relative) uncertainty?
Answer: (C)
The number of significant figures sets the relative uncertainty of a measurement, not the number of decimal places or the size of the unit. Take the relative uncertainty as (±1 in the last digit) ÷ (the value). For 0.0820 kg it is 0.0001/0.0820 ≈ 1.2×10⁻³. For 9.7 m it is 0.1/9.7 ≈ 1.0×10⁻². For 1.002×10³ s it is 1/1002 ≈ 1.0×10⁻³. For 5.00×10⁻³ A it is 0.01/5.00 = 2×10⁻³. The smallest is 1.002×10³ s, the measurement with four significant figures.
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All 35 real JEE Advanced questions from Physical World and Measurement.
The questions from the actual papers, with the official answer and an explanation for each — chapter by chapter, or as full timed papers.
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About Physical World and Measurement in JEE Advanced.
How many questions come from Physical World and Measurement in JEE Advanced?
Physical World and Measurement (Physics, Class 11) has been asked 35 times in the 40 JEE (Advanced) papers from 2007–2026: about 0.9 questions a paper, 5% of all Physics questions. It is the 10th most-asked of 19 Physics chapters. The two 2026 papers had 2 from it.
Which topics of Physical World and Measurement are asked most in JEE Advanced?
Dimensional analysis (16), Error analysis (15), Units and dimensions (3), Significant figures (1), counted over the papers from 2007–2026.
Is Physical World and Measurement important for JEE Advanced 2027?
It is in the syllabus in force, so it can be asked. By past papers it ranks 10 of 19 in Physics; use that to decide how much time it gets, not whether to study it.
Where can I solve Physical World and Measurement JEE Advanced previous year questions?
On Nikaalle, free: sign up and practise every past JEE Advanced question from Physical World and Measurement with an explanation for each, or sit the full papers timed. The ten questions on this page are our own, written in the same pattern.
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