Units and Measurement

Introduction:
Natural laws are explained in a unique way in Physics. This explanation includes a quantitative description, comparison, and measurement of various physical quantities. We must first create a standard unit of measurement before we can measure or compare a physical quantity. The weight of a lion is more than that of a goat. However, how many times have you done that before? Prashant towers over Robin, but by how much? To answer such questions, we'll need to build a unit. We can calculate that the lion's weight is 200 times that of a goat if the mass is the unit. If we take the length as a unit, we can easily conclude that Robin is 2 times the unit taller than Prashant.

We need a universally acquired standard called a Unit to measure any quantity or compare two quantities. Any physical quantity is measured using a number and a specific unit.

Quantity X Unit = Measurement

List of topics according to NCERT and JEE Main/NEET syllabus:

unit of measurement Subtopics:

1. Units that are fundamental and derived
2. Instruments with the highest accuracy, precision, and the lowest count
3. Measurement errors
4. Figures of importance
5. Physical quantities' dimensions
6. SI Units
7. Absolute Errors
8. Significant Figures
9. Dimensional Analysis

Approximately 4% of questions come from the topic in JEE Mains and NEET.

Related Topics,

Important concepts and Laws:

• Physics-scope and excitement;
• Nature of physical laws;
• Physics,
• technology and society. (To be discussed as a part of Introduction and integrated with other topics)
• Need for measurement:
• Units of measurement;
• Systems of units;
• SI units,
• Fundamental and derived units.
• Length, mass and time measurements
• Accuracy and precision of measuring instruments;
• Errors in measurement;
• Significant figures.
• Dimensions of physical quantities
• Dimensional analysis and its applications
• Some important formulas of conversions are also written below
• converting lengths,
• 1 millimeter to cm :- 1cm = 10mm
• inches to metric :- 1 inch = 25.4 mm , 1 mm = 0.0393700787 in
• 1 inch in centimeters / centimeters to inches :- 1 inch = 2.54 centimeters.
• 1 acre in bigha:- One acre = 1.62 bigha
• sq metres to sq ft :- 1 square meter = 10.764 feet
• 1 bigha in square feet :- 1 bigha = 27,000 square feet.
• bigha to acre :- 1 Bigha= 0.6198347 Acre.
• 1 bigha in gaj :- 1 Bigha = 1,954.766117441 Gaj
• sq metres to acres :- 4046.8564224 square meters = 1 acre
• 1 litre in millilitres :- 1 litre = 1000 ml,
• metric ton to kg / 1 metric tonnes to kg :- 1000 kilograms = 1 metric tons
• kilowatt-hour is the unit of electricity consumption which is also called as 1 unit of electricity

NCERT Notes Subject Wise Link:

• NCERT notes Class 11 Maths
• NCERT notes Class 11 Physics
• NCERT notes Class 11 Chemistry
• NCERT notes Class 11 Biology

Importance of Units and Measurement class 11:

The topic is crucial to understand since there will be no uniformity in measurement without a standard unit system. The only way to verify the correctness of any hypothesis is to use measurements. As a result, understanding Units and Measurements is critical because it deals with a comparison tool. Though it is a part of the school curriculum, namely the Physics syllabus for class 11, it is used in our daily lives. A review of the subjects covered in the following class XI Physics chapter will give you an idea of what to expect.

NCERT Solutions Subject wise link:

• NCERT solutions for class 11 Physics.
• NCERT solutions for class 11 Chemistry.
• NCERT solutions for class 11 Mathematics.
• NCERT solutions for class 11 Biology.

NCERT Exemplar Solutions Subject wise link:

• NCERT exemplar solutions for class 11 Physics.
• NCERT exemplar solutions for class 11 Chemistry.
• NCERT exemplar solutions for class 11 Mathematics.
• NCERT exemplar solutions for class 11 Biology.