In Physics, SI units and dimensional analysis form the foundation for solving numerical problems, verifying equations, and understanding the physical meaning behind quantities. Whether you’re preparing for competitive exams or strengthening your conceptual base, practising MCQs on SI units and dimensional analysis is one of the most effective ways to improve accuracy and speed.

For students preparing for NEET, JEE, and CUET, mastering SI units and dimensional analysis is especially important because many numerical problems rely on correct unit conversions, dimensional consistency checks, and interpretation of fundamental constants. Whether it is verifying whether an equation is dimensionally valid or identifying the right SI unit for a given quantity, these concepts ensure accuracy and avoid conceptual mistakes.

This blog post brings you a comprehensive set of MCQs on SI units and dimensional analysis, covering everything from inductance and magnetic flux to gravitational constant, polarizability, and thermal conductivity. Each question includes options and correct answers, helping you revise efficiently and strengthen the chapters that repeatedly appear in entrance exams.

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• SI units class 11 physics

• dimensional analysis MCQs

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• dimensional formula questions

• fundamental units in physics with examples

• dimensional formula and dimensional equations

• derived units in physics explained

• units and measurements class 11 important concepts

• difference between CGS MKS and SI system

• converting physical units in physics

• what are base quantities and derived quantities

• dimensional consistency and homogeneity

• how to check physical dimensions of a quantity

• applications of dimensional analysis in real life

MCQs on SI Units and Dimensional Analysis

1. In SI units, kg·m²·s⁻² is equivalent to which of the following?

a) newton
b) watt
c) joule
d) pascal
Answer: c

2. If the unit of length, mass, and time each be doubled, the unit of work is increased by

a) 2 times
b) 4 times
c) 6 times
d) No change
Answer: a

3. If E and H represent electric field intensity and magnetising field respectively, the unit of E/H is

a) ohm
b) mho
c) joule
d) newton
Answer: a

4. The unit of current element is

a) A m
b) A m⁻¹
c) A m²
d) A m⁻²
Answer: a

5. A force F = P tᵃ Q t acts on a body. The unit of P must be same as

a) Displacement
b) Velocity
c) Acceleration
d) Momentum
Answer: d

6. If time (t), velocity (v) and angular momentum (l) are fundamental units, the dimension of mass (m) is

a) [t v² l³]
b) [t² v² l]
c) [t² v⁻¹ l]
d) [t⁻¹ v⁻² l]
Answer: d

7. Which of the following is NOT a unit of time?

a) Lunar month
b) Light year
c) Leap year
d) Microsecond
Answer: b

8. The unit of magnetic induction is

a) Wb m⁻²
b) Wb m⁻¹
c) Wb A
d) Wb
Answer: a

9. If 1 new unit of length = x meter, then 1 m² expressed in new unit is

a) x
b) x²
c) 1/x
d) 1/x²
Answer: d

10. The SI unit of inductance is

a) kg m² s⁻² A⁻²
b) kg s⁻² A⁻¹
c) kg m² s⁻³ A⁻²
d) kg m² s⁻³ A⁻²
Answer: a

11. The unit of L/R is

a) sec
b) sec⁻¹
c) volt
d) ampere
Answer: a

12. Unit of magnetic flux is

a) Tesla
b) Gauss
c) Weber
d) Weber/m²
Answer: c

13. Which of the following combinations can never be meaningful?

a) P − Q
b) PQ − R
c) PQ
d) PR − Q²
Answer: a

14. SI unit of inductance is

a) Ampere
b) Ohm
c) Henry
d) Faraday
Answer: c

15. The unit of relative permittivity is

a) C² N⁻¹ m⁻²
b) Nm² C⁻²
c) unitless
d) m² C⁻¹
Answer: c

16. Which of these is both unitless and dimensionless?

a) Angle
b) Solid angle
c) Mechanical equivalent of heat
d) Refractive index
Answer: d

17. The CGS unit of magnetic field (Biot–Savart law) is

a) Tesla
b) Gauss
c) Tesla·m/A
d) Newton/Amp
Answer: b

18. If mass = A kg, length = B m, time = C s, then 10 N equals

a) 10 A⁻¹ B⁻¹ C⁻²
b) 10 A⁻¹ B⁻¹ C
c) 10 A B C⁻²
d) 5 A⁻¹ B⁻¹ C
Answer: b

19. kg·m⁻¹·s⁻²·A⁻³ is the SI unit of

a) Inductance
b) Resistance
c) Capacitance
d) Magnetic flux
Answer: b

20. Dioptre is the unit of

a) Power of lens
b) Focal length
c) Ionosphere
d) None
Answer: a

21. Which of the following is NOT a unit of surface tension?

a) N m
b) J m²
c) kg s⁻²
d) W m
Answer: d

22. The unit of polarizability is

a) C² m N⁻¹
b) C² m⁻¹
c) C² m N⁻¹
d) C² m⁻¹
Answer: a

23. Correct unit of thermal conductivity is

a) J m⁻² s⁻¹ °C⁻¹
b) J m⁻¹ s⁻¹ °C⁻¹
c) J s⁻¹
d) J m⁻¹ s⁻¹ (°C)⁻¹
Answer: d

24. SI unit of gravitational constant is

a) N m kg⁻²
b) N m² kg⁻²
c) C² N⁻¹
d) N m⁻²
Answer: b

25. ______ system of units was accepted by the General Conference on Weights and Measures.

a) FPS
b) CGS
c) MKS
d) SI
Answer: d

26. SI unit of mechanical equivalent of heat is

a) J/cal
b) J–cal
c) erg/J
d) erg/J
Answer: a

27. Siemen is the SI unit for

a) Electrical resistivity
b) Electrical conductance
c) Electrical permittivity
d) Electrical capacitance
Answer: b

28. SI unit of moment of inertia is

a) kg m⁻²
b) kg m²
c) N m⁻²
d) N m²
Answer: b

29. If x = a t + b t² (x in km, t in s), the unit of b is

a) km/s
b) km·s
c) km/s²
d) km·s²
Answer: c

30. Unit of permittivity of free space (ε₀) is

a) coulomb/newton·metre
b) newton·metre²/coulomb²
c) coulomb²/newton·metre²
d) coulomb²/(newton–metre)²
Answer: c

Conclusion

Mastering SI units and dimensional analysis is essential for achieving precision in Physics. These MCQs help strengthen your conceptual clarity, improve your analytical skills, and prepare you for competitive exams like NEET, JEE, CUET, and board-level assessments. With consistent practice, the rules of SI units and dimensional analysis become intuitive, making problem-solving faster and more accurate.Remember—physics becomes significantly simpler when the underlying units make sense. Keep revising these concepts regularly, maintain a formula sheet for quick reference, and continue solving topic-wise MCQs to reinforce your preparation. With strong command over SI units and dimensional analysis, you build a rock-solid foundation for all higher-level chapters in mechanics, electromagnetism, and modern physics.