Class 11 Physics — Chapter 1: Units and Measurement

What you'll learn

• ▸Fundamental and Derived Units
• ▸The SI System of Units
• ▸Significant Figures
• ▸Arithmetic Operations with Significant Figures
• ▸Dimensions of Physical Quantities
• ▸Dimensional Analysis and its Applications

Chapter Summary

--- PAGE 1 --- CHAPTER ONE UNITS AND MEASUREMENT 1.1 Introduction 1.2 The international system of units 1.3 Significant figures 1.4 Dimensions of physical quantities 1.5 Dimensional formulae and dimensional equations 1.6 Dimensional analysis and its applications Summary Exercises 1.1 INTRODUCTION Measurement of any physical quantity involves comparison with a certain basic, arbitrarily chosen, internationally accepted reference standard called **unit**. The result of a measurement of a physical quantity is expressed by a number (or numerical measure) accompanied by a unit. Although the number of physical quantities appears to be very large, we need only a limited number of units for expressing all the physical quantities, since they are inter- related with one another. The units for the fundamental or base quantities are called **fundamental or base units**. The units of all other physical quantities can be expressed as combinations of the base units. S…

Practice Questions from this Chapter

Tap "Get Solution" on any question to ask our AI tutor.

1. Compare CGS and MKS units. Get Solution →
2. Define what makes a good unit. Get Solution →
3. Show real-world uses of radians. Get Solution →
4. What is a basic, internationally accepted reference standard used for comparing physical quantities called? Get Solution →
5. What are the units for the fundamental or base quantities called? Get Solution →
6. Which of the following is an older system of units mentioned in the text? Get Solution →
7. What does the abbreviation 'SI' stand for? Get Solution →
8. How many base units are there in the SI system? Get Solution →

Did you know?

• 💡 The original kilogram was a physical metal cylinder stored in France for over 130 years.
• 💡 The length of a 'foot' unit once varied because it was based on a king's actual foot.
• 💡 An atomic clock, defining the second, loses only one second in 300 million years.
• 💡 The Kelvin temperature scale has no negative numbers; it measures absolute energy.
• 💡 The speed of light is precisely defined, and then used to define the length of a meter.

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