- Amal Augustine
- November 28, 2025
Crack NEET JEE & CUET with this Comprehensive MCQ Guide on Units, Measurements & Dimensional Logic
Understanding units, dimensions, dimensional analysis, and the SI system forms the backbone of Class 11 Physics and competitive exams like NEET, JEE, CUET, and state-level entrance tests. This chapter repeatedly appears in objective sections, especially in problems involving conversion of units, dimensional consistency, fundamental and derived units, order of magnitude, magnetic flux, Planck’s constant, and error-free calculation of physical quantities.
This article compiles a unique set of MCQs, each supported by keywords relevant to competitive exams, to help students build mastery and confidence.
Why Units & Measurements Matter
Before solving numerical problems or equations, students must ensure they are working with the correct physical units. Questions commonly test:
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SI unit conversions
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Dimensional formulas
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Fundamental vs derived quantities
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Unit analysis in new physical systems
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Electromagnetic units (Weber, Gauss, Henry, Tesla, Ampere-meter, etc.)
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Prefixes such as giga, milli, atto, micro
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Order of magnitude
These areas are crucial in exams such as NEET, JEE Main, JEE Advanced, and CUET Science because they check conceptual precision rather than memorization.
MCQs with Options and Correct Answers
1. SI unit of inductance is
A) Ampere
B) Ohm
C) Henry ✔️
D) Faraday
2. Which combination can never be meaningful if P, Q, R have different dimensions?
A) P – Q/R ✔️
B) PQ – R
C) PQ/R
D) PR – Q²/R
3. Unit of magnetic flux is
A) Tesla
B) Gauss
C) Weber ✔️
D) Weber/m²
4. Unit of L/R is
A) Second (sec) ✔️
B) sec⁻¹
C) volt
D) ampere
5. The SI unit of inductance is
A) Kg m² s⁻² A⁻² ✔️
B) Kg s⁻² A⁻¹
C) Kg m² s⁻² A⁻¹
D) Kg m² s⁻³ A⁻²
6. If 1 new unit of length = x meters, then area of 1 m² in new units is
A) x
B) x²
C) 1/x
D) 1/x² ✔️
7. Unit of magnetic induction is
A) Wb m⁻² ✔️
B) Wb m⁻¹
C) Wb A
D) Wb
8. Which is not a unit of time?
A) Lunar month
B) Light year ✔️
C) Leap year
D) Microsecond
9. Dimension of mass in terms of t, v, l
A) t⁻¹ v¹ l⁻²
B) t¹ v² l⁻¹
C) t² v⁻¹ l¹
D) t⁻¹ v⁻² l¹ ✔️
10. For F = P tᵃ Q t, unit of P must match
A) Displacement
B) Velocity
C) Acceleration
D) Momentum ✔️
11. Unit of current element is
A) A·m ✔️
B) A·m⁻¹
C) A·m²
D) A·m⁻²
12. Unit of E/H is
A) Ohm ✔️
B) Mho
C) Joule
D) Newton
13. If L, M, T units are doubled, work increases by
A) 2 times ✔️
B) 4 times
C) 6 times
D) No change
14. kg·m²·s⁻² is equal to
A) Newton
B) Watt
C) Joule ✔️
D) Pascal
15. SI unit of Stefan–Boltzmann constant σ is
A) W m⁻² K⁻⁴ ✔️
B) W m² K⁻⁴
C) W K⁻⁴
D) erg s⁻¹ K⁻⁴
16. Unit of magnetic moment is
A) A·m² ✔️
B) A·m
C) A·m³
D) kg·m²
17. SI unit of specific resistance is
A) ohm/m²
B) ohm/m³
C) ohm·m ✔️
D) ohm/m
18. In star units, value of 1 J is
A) 2.4 × 10⁻⁵
B) 3.6 × 10⁻⁴ ⋆J ✔️
C) 4.2 × 10⁻³
D) 4.2 × 10⁻² ⋆J
19. SI value of Planck’s constant
A) 6.63×10⁻³⁴ Js
B) 6.63×10⁻³⁰ kg·m²
C) 6.63×10⁻³⁴ kg·m²
D) 6.63×10⁻³⁴ kg ✔️
(Note: trick question — “kg” alone is incorrect physically but marked as per provided key.)
20. Quantity with 10³ ratio between SI and CGS
A) Universal gravitational constant ✔️
B) Boltzmann constant
C) Planck constant
D) Young’s modulus
21. 0.625 g/cm³ = ? in SI
A) 0.625
B) 0.0625
C) 0.00625
D) 625 ✔️
22. Not a fundamental unit
A) Length
B) Mass
C) Magnetic field ✔️
D) Current
23. Prefix “giga” means
A) 10⁻⁹
B) 10⁹ ✔️
C) 10⁶
D) 10⁻⁶
24. Speed of bus at 110 km/h in m/s
A) 30.6 m/s ✔️
B) 60.2 m/s
C) 40 m/s
D) 50.4 m/s
25. Prefix “atto” means
A) 10⁻²¹
B) 10⁻¹⁵
C) 10⁻¹⁸ ✔️
D) 10⁻¹²
26. Pick out the stranger
A) Newton–Meter
B) Coulomb–Volt
C) Coulomb–Farad ✔️
D) Watt–Second
27. Major contribution of C.V. Raman
A) Photoelectric effect
B) Buoyancy principle
C) Scattering of light by molecules ✔️
D) Electromagnetic theory
28. Distance of star if light takes 10 years
A) 9.46×10¹⁶ m ✔️
B) 9.46×10⁻¹⁶ m
C) 9.46×10¹⁷ m
D) 9.46×10⁻¹⁷ m
29. Order of magnitude is
A) Power of 5
B) Power of 10 ✔️
C) Power of 100
D) Power of 0.01
30. If 10 g·cm·s⁻¹ = x N·s, then x =
A) 1×10⁻⁵ ✔️
B) 1×10⁻⁴
C) 1×10⁻⁶
D) 1×10⁻³
Final Thoughts for Competitive Exam Students
Mastering unit conversion, dimensional formulas, and special electromagnetic units such as Henry, Weber, Tesla, Siemen, ohm·meter, and A·m² gives students a strong advantage in scoring full marks in physics MCQ sections. Questions from this topic consume very little time, making them high-value scoring opportunities.
Amal Augustine is the founder of ExQuizMe, a dynamic learning and quiz platform built to make education engaging, competitive, and fun. A passionate learner and an academic achiever, Amal completed his schooling at Government HSS Manjapra, graduating with 92.5% in Computer Science. He later earned his degree from St. Stephen’s College, University of Delhi, one of India’s most prestigious arts and science institutions.
Currently, Amal is pursuing his Master’s degree at National Sun Yat-sen University, Taiwan, where he continues to deepen his interest in research and technology. Throughout his school and college years, he won 50+ national-level interschool and collegiate quiz competitions, was
Beyond academics, Amal Augustine is an avid reader of science journals, a dedicated research student, and a technology enthusiast who loves programming and exploring the world of Computer Science. Through ExQuizMe, he aims to make learning accessible, enjoyable, and empowering for students across the globe.