NCERT  ·  Physics  ·  Class XI  ·  Ch.1

Units and Measurement
MCQ Master Series

SI Units · Dimensions · Dimensional Analysis · Errors · Significant Figures

🎯 50 Questions
⏱ 40 min Suggested
📊 3 Tiers
🗂 5 Topics
⚡ Start Quiz 📊 Analytics
Scroll
Question Intelligence

Quiz Analytics

A data-driven breakdown of all 50 questions by difficulty, exam origin and topic distribution.

📈 Distribution Overview

50
Total Questions
Concept Check (NCERT Basics)
22
Boards / JEE Main Level
20
JEE/NEET Edge / HOTS
8

🗂 Topic Coverage

SI Base & Derived Units
24%
Dimensional Formulae & Tables
28%
Dimensional Consistency & Equations
20%
Deriving Relations via Analysis
16%
Dimensionless Numbers & Orders
12%
22
Concept Check (NCERT Basics)
20
Boards / JEE Main Level
8
JEE/NEET Edge / HOTS
Conceptual Framework

Key Concept Highlights

6 foundational pillars that power every question in this quiz. Understand these, and the answers follow naturally.

📏
Base vs Derived Quantities
Seven SI base quantities with their units form the foundation, while all other physical quantities use derived units built as combinations of these base units.
📐
Dimensional Formulae
Every physical quantity can be expressed in terms of fundamental dimensions like M, L and T, allowing you to represent force, work, pressure and many others in a compact symbolic form.
🧮
Dimensional Analysis Techniques
By equating dimensions on both sides of an equation, you can check consistency, spot errors and even derive relations such as pendulum period or escape velocity up to dimensionless constants.
⚖️
Dimensionless Quantities & Numbers
Ratios like Reynolds number, Mach number and pure numbers such as Avogadro number or orders of magnitude have no dimensions but carry powerful physical meaning.
📊
Limits of Dimensional Analysis
Dimensional analysis cannot give numerical constants, cannot distinguish between two different dimensionally correct equations and fails when dimensionless functions are involved.
✍️
Significant Figures & Error Sense
Precision of a measurement is encoded through significant figures, while error analysis tells you how uncertainties in measured quantities propagate into derived results.
Pedagogical Value

Why MCQs Matter

Multiple-choice questions are not mere guessing games — they are the sharpest diagnostic tool available to a competitive exam aspirant.

~6–8%
of Class XI Physics weightage via SI base/derived units, dimensional analysis, significant figures and error‑based questions in Boards & JEE/NEET.
Quick Reference

Important Formula Capsules

10 must-memorise equations that surface repeatedly across CBSE and JEE papers.

Physical Quantity Representation
\[ Q = n \times \text{unit} \]
Dimensions of Velocity
\[ [v] = LT^{-1} \]
Dimensions of Acceleration
\[ [a] = LT^{-2} \]
Dimensions of Force
\[ [F] = MLT^{-2} \]
Dimensions of Work/Energy
\[ [W] = [E] = ML^{2}T^{-2} \]
Dimensions of Pressure
\[ [P] = ML^{-1}T^{-2} \]
Dimensions of Angular Momentum
\[ [L] = ML^{2}T^{-1} \]
Planck’s Constant
\[ [h] = ML^{2}T^{-1} \]
Gravitational Constant
\[ [G] = M^{-1}L^{3}T^{-2} \]
Permittivity of Free Space
\[ [\epsilon_{0}] = M^{-1}L^{-3}T^{4}I^{2} \]
Learning Outcomes

What You Will Learn

By completing this quiz set you will have exercised all the following competencies.

01 Identify which quantities are SI base quantities, which are derived and choose the correct SI unit for each physical quantity appearing in the questions.
02 Write and interpret dimensional formulae for common quantities like force, work, pressure, viscosity, surface tension, charge and universal constants.
03 Use dimensional analysis to test whether given equations and options are dimensionally consistent or inconsistent, eliminating impossible relations quickly.
04 Apply dimensional analysis to obtain proportional relations such as the dependence of period, escape velocity or orbital time on physical parameters.
05 Recognise dimensionless quantities and special numbers like Reynolds number, Mach number and Avogadro number, and understand why their dimension is M^{0}L^{0}T^{0}.
06 Use order of magnitude ideas and dimensional reasoning together with physical insight to choose the most reasonable option in conceptual and numerical MCQs.
Exam Preparation

Strategy & Preparation Tips

5 evidence-based strategies to maximise your score in CBSE Boards and JEE.

Step 01
Memorise Base & Key Derived Units
First lock in the seven SI base quantities with units and a small table of high‑frequency derived units (N, J, W, Pa, C, V, Ω); this makes many unit‑based MCQs almost instant.
Step 02
Always Check Dimensions First
Whenever you face an unfamiliar formula or multi‑option relation, quickly write dimensional forms on rough work; one glance is often enough to discard wrong expressions.
Step 03
Use DA to Derive Relations
Practise deriving dependencies like \(T \propto l^{1/2}g^{-1/2}\) or \(v_{esc} \propto (GM/R)^{1/2}\) by dimensional analysis so similar questions in JEE/NEET feel routine.
Step 04
Respect Dimensionless Numbers
Treat Reynolds number, Mach number and other ratios as pure numbers with no unit; any option giving them non‑zero dimensions is automatically wrong.
Step 05
Combine DA with Physical Sense
Remember that dimensional analysis cannot give numerical factors or distinguish between two dimensionally correct forms; use graphs, limits and physical intuition for the final decision.

Ready to Test Your Mastery?

50 questions  ·  Elapsed timer  ·  Instant scored results

⚡ Begin Units and Measurement Quiz
🔭

No MCQs Found

We couldn't find questions for this selection. Try a different topic.

UNITS AND MEASUREMENT — Learning Resources

📄 Detailed Notes
✔️ True / False
📌 Exercise
💬 Q&A Discussion
🎯 Advance MCQs
📝 Exercises
UNITS AND MEASUREMENT-Exercise

Get in Touch

Let's Connect

Questions, feedback, or suggestions?
We'd love to hear from you.