Class 9th · Physics · Chapter 1
Chapter 1: Physical Quantities and Measurements
Chapter 1 of the Punjab Board Class 9th Physics textbook runs from page 5 to 27 and covers 12 topics. Its exercise has multiple choice questions, short / constructed response questions, comprehensive questions and numerical problems. Open any of those pages in GenZ Books, tap a question, and the answer is worked from this chapter.
Open Chapter 1 of Physics in GenZ Books
The same Class 9th textbook, page for page. Tap any question and get the answer worked from that chapter — English and Urdu.
What you will learn
- Differentiate between physical and non- physical quantities
- Explain with examples that physics is based on physical quantities [Including that these consist of a magnitude and a unit]
- Differentiate between base and derived physical quantities and units
- Use the seven units of System International (SI) along with their symbols and physical quantities (standard definitions of SI units are not required)
- Analyse and express numerical data using scientific notation [in measurements, and calculations.]
- Analyse and express numerical fe using prefixes [interconverting the prefixes and their symbols to indicate multiple and submultiple for both base and derived units.]
- Justify and illustrate thé.Use of common lab instruments to measure length [Including least count.ofinstruments and how to measure a variety of lengths with appropriate precision using Tapes, Rulers and Vernier Callipers and Micrometres (including reading the scale on analogue and digital callipers and micrometres)]
- Justify and‘illustrate the use of measuring cylinders to measure volume [Including both measurement of volumes of liquids and determining the volume of a so
Topics in this chapter
- 1.1Physical and Non-Physical Quantitiesp. 6
- 1.2Base and Derived Physical Quantitiesp. 7
- 1.3International Systemp. 8
- 1.4Scientific Notation sentp. 10
- 1.5Length Measuring Instrumentsp. 11
- 1.6Mass Measuring Instrumentsp. 16
- 1.7Time Measuring Instrumentsp. 17
- 1.8Volume Measuring Instrumentsp. 17
- 1.10Uncertainty in a Measurementp. 20
- 1.11Significant Figuresp. 20
- 1.12Precision and Accuracyp. 21
- 1.13Rounding off the Digitsp. 22
Exercise
- Multiple Choice Questionsp. 24
- Short / Constructed Response Questionsp. 25
- Comprehensive Questionsp. 26
- Numerical Problemsp. 27
GenZ Books has 15 questions from this chapter catalogued, each answered from the pages above.
A sample answer from GenZ Books
Explain · page 25: ShortAnswerQuestions اظ 1.1. Cananon-physical quantity be measured? If yes, then how?
Hey there! That's a great question to start with, as it really helps you understand the core of what physics is all about.
The simple answer is that non-physical quantities (غیر طبیعی مقداریں) cannot be measured. Only physical quantities (طبیعی مقداریں) can be measured.
Here’s why:
- Physical Quantities: These are things that can be measured directly using instruments and expressed with a numerical value and a specific unit. For example, you can measure the length of your desk with a meter rule (e.g., 1.2 meters), the mass of your school bag with a balance (e.g., 5 kilograms), or the time it takes to walk to school with a stopwatch (e.g., 15 minutes). These all have standard units and tools for measurement.
- Non-Physical Quantities: These are concepts, feelings, or qualities that don't have a numerical value or a standard unit. Things like happiness, beauty, honesty, sadness, or intelligence are non-physical quantities. You can describe them, but you can't assign a number and a unit to them using a measuring instrument.
For example, imagine you're watching a cricket match. You can measure the speed of the bowler's ball (a physical quantity) in kilometers per hour, or the time the match lasts (another physical quantity) in hours. But you can't measure "how exciting" the match was (a non-physical quantity) in any standard unit. You might say it was "very exciting" or "a bit boring," but you can't give it a number like "7.5 excitement units."
A common mistake is to think that if you can describe something as "more" or "less," it must be measurable. While you can say one person is "more intelligent" than another, or one painting has "more beauty," these are comparisons, not measurements with standard units. You can't use a "beauty-meter" or an "intelligence-scale" in the same way you use a ruler for length.
In short: Only physical quantities, which have a numerical value and a standard unit, can be measured.
AI-generated from the chapter text by GenZ Books. It can make mistakes — check it against your textbook and your teacher.