Units, Dimensions & Errors — JEE Main PYQs & Practice Questions

Units, Dimensions & Errors is a Physics chapter in the JEE Main syllabus. This page brings together 184 previous-year and practice questions on Units, Dimensions & Errors, organised into 4 topics: SI Units and Dimensions, Dimensional Analysis, Significant Figures and Error Analysis. Most questions come with a step-by-step solution you can work through free in PrepWiser.

Download Units, Dimensions & Errors JEE Main PYQs as a free PDF (with answer key)

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SI Units and Dimensions

• A new unit ( α ) of length is chosen such that it is equal to the speed of light in…
• The SI unit of power is:
• Match List I with List II. List I | List II; A. | Torque | I. | Nms⁻¹; B. | Stress | II…
• If ε,E and t represent the free space permittivity, electric field and time…
• The SI unit of work is:
• Match the LIST-I with LIST-II LIST-I | LIST-II ; A. | Boltzmann constant | I | ML² T⁻¹…
• The SI units of the universal gravitational constant G are:
• The SI unit of pressure is:
• Match List - I with List - II. List - I | List - II; (a) | R_H (Rydberg constant) | (i)…
• Match List I with List II : List I | List II ; A. | Torque | I. | kgm⁻¹ s⁻²; B. | Energy…
• The SI unit of Young's modulus is:
• In an expression a× 10ᵇ :
• Match List I with List II List I | List II; A. | Surface tension | I. | kg m⁻¹ s⁻¹; B. |…
• Given below are two statements : Statements I : Astronomical unit (Au), Parsec (Pc) and…
• Suppose you have taken a dilute solution of oleic acid in such a way that its…
• Match List I with List II LIST I | LIST II; A. | Torque | I. | ML⁻²T⁻²; B. | Stress |…
• Velocity (v) and acceleration (a) in two systems of units 1 and 2 are related as…
• Match List I with List II LIST I | LIST II; A. | Spring constant | I. | [T⁻¹]; B. |…
• Which of the following is a base SI unit?
• If E and H represents the intensity of electric field and magnetising field…

Dimensional Analysis

• Dimensions of universal gravitational constant (G) in terms of Planck's constant (h)…
• Given below are two statements : One is labelled as Assertion A and the other is…
• In the equation [X+a/Y²][Y-b]=RT,X is pressure, Y is volume, R is universal gas constant…
• Dimensional formula for thermal conductivity is (here K denotes the temperature):
• The work done by a gas molecule in an isolated system is given by, W=αβ²e^(-x²/(α kT))…
• A quantity x is given by (IFv²/WL⁴) in terms of moment of inertia I, force F, velocity…
• Which of the following physical quantities have the same dimensions?
• Given below are two statements : Statement (I) : Planck's constant and angular momentum…
• Match List I with List II LIST I | LIST II ; A. | Angular momentum | I. | [ML² T⁻²]; B…
• In a typical combustion engine the workdone by a gas molecule is given by…
• The potential energy of a particle changes with distance x from a fixed origin as…
• Assume that the displacement(s) of air is proportional to the pressure difference (Δp)…
• Match the LIST-I with LIST-II List-I | List-II; A. | Spring constant | I. | ML²T⁻²K⁻¹…
• Given a charge q , current I and permeability of vacuum μ_(o^∗). Which of the following…
• The position of a particle moving on x-axis is given by x(t)=A sin t+B cos² t+Ct²+D…
• The dimension of B²/2μ₀, where B is magnetic field and μ₀ is the magnetic permeability…
• The dimensional formula of 1/2ε₀E² (ε₀ = permittivity of vacuum and E = electric field)…
• Which one of the following is the correct dimensional formula for the capacitance in F ?…
• In a measurement, it is asked to find modulus of elasticity per unit torque applied on…
• Dimension of 1/(μ₀∈₀) should be equal to

Significant Figures

• The number of significant figures in 1.050 × 10³ is:
• Using rules of significant figures, the product 2.5 × 1.25 should be reported as:
• The number of significant figures in 0.00250 is:

Error Analysis

• The density ρ of a uniform cylinder is determined by measuring its mass m, length l and…
• In an experiment to determine the Young's modulus of wire of a length exactly 1 m, the…
• The density of a solid metal sphere is determined by measuring its mass and its…
• The radius (r), length (l) and resistance (R) of a metal wire was measured in the…
• The percentage error in the calculated volume of a sphere, if there is 2% error in its…
• Keeping the significant figures in view, the sum of the physical quantities 52.01 m…
• A quantity Q is formulated as X⁻²Y^(+3/2)Z^(-2/5). X, Y, and Z are independent…
• A physical quantity 'y' is represented by the formula y=m²r⁻⁴gˣl^(-3/2) If the…
• A physical quantity z depends on four observables a, b, c and d, as z = a²b^(2/3)/√cd³…
• The diameter of a wire measured by a screw gauge of least count 0.001 cm is 0.08 cm. The…
• A person measures mass of 3 different particles as 435.42 g,226.3 g and 0.125 g…
• For an experimental expression y=(32.3× 1125)/27.4, where all the digits are…
• For z=a²x³y^(1/2), where 'a' is a constant. If percentage error in measurement of 'x'…
• The period of oscillation of a simple pendulum is T = 2π √(L/g). Measured value of 'L'…
• A physical quantity C is related to four other quantities p,q,r and s as follows…
• Two resistors R₁ = (4 ± 0.8) Ω and R₂ = (4 ± 0.4) Ω are connected in parallel. The…
• A spherical body of radius r and density σ falls freely through a viscous liquid having…
• The measured value of the length of a simple pendulum is 20 cm with 2 mm accuracy. The…
• A physical quantity P is given as P=a²b³/c√d<?p> The percentage error in the measurement…
• If the percentage errors in measuring the length and the diameter of a wire are 0.1%…

More Physics chapters

• Basic Mathematics for Physics
• Rectilinear Motion
• Vectors
• Projectile Motion & Relative Motion
• Newton's Laws of Motion
• Friction
• Circular Motion
• Work, Energy & Power
• Centre of Mass & Linear Momentum
• Collision
• Rotational Motion
• Gravitation
• Simple Harmonic Motion
• Elasticity
• Fluid Mechanics
• Surface Tension
• Thermometry & Calorimetry
• Kinetic Theory of Gases
• Thermodynamics
• Heat Transfer
• Mechanical Waves
• Sound Waves
• Experimental Skills
• Electrostatics I — Charges, Field & Gauss's Law
• Electrostatics II — Potential & Capacitance
• Current Electricity
• Moving Charges & Magnetism
• Magnetism & Matter
• Electromagnetic Induction
• Alternating Current
• Electromagnetic Waves
• Ray Optics
• Wave Optics
• Dual Nature of Radiation & Matter
• Atomic Physics
• Nuclear Physics
• Semiconductors & Electronic Devices
• Communication Systems

Frequently asked questions

How many Units, Dimensions & Errors questions are there for JEE Main?

PrepWiser has 184 Units, Dimensions & Errors questions for JEE Main, grouped into 4 topics such as SI Units and Dimensions, Dimensional Analysis and Significant Figures.

Are these Units, Dimensions & Errors questions from previous-year JEE Main papers?

Yes — most are genuine previous-year questions from past JEE Main papers, and the rest are practice questions written to match the JEE Main pattern and difficulty.

Where can I see the answers and solutions to these Units, Dimensions & Errors questions?

Open any Units, Dimensions & Errors question in PrepWiser (it is free) to attempt it; most come with a step-by-step solution.