Below is a concise list of key definitions from Chapter 1: Measurements of the 11th Class Physics syllabus for the Federal Board of Intermediate and Secondary Education (FBISE)

 Below is a concise list of key definitions from Chapter 1: Measurements of the 11th Class Physics syllabus for the Federal Board of Intermediate and Secondary Education (FBISE),

 based on the National Book Foundation (NBF) curriculum. These definitions align with the concepts typically covered in this chapter, focusing on physical quantities and measurement.

1. Physics: The branch of science that deals with the study of matter, energy, and their interactions.
2. Physical Quantity: A property of a physical system that can be measured and expressed numerically (e.g., length, mass, time).
3. Fundamental Quantity: A physical quantity that is independent and not defined in terms of other quantities (e.g., length, mass, time, electric current, temperature, amount of substance, luminous intensity).
4. Derived Quantity: A physical quantity defined in terms of fundamental quantities (e.g., speed, area, density).
5. Unit: A standard quantity used to express and measure a physical quantity (e.g., meter for length, kilogram for mass).
6. Fundamental Unit: A unit corresponding to a fundamental quantity (e.g., meter, kilogram, second).
7. Derived Unit: A unit defined as a combination of fundamental units (e.g., m/s for speed, kg/m³ for density).
8. International System of Units (SI): A globally accepted system of units for measuring physical quantities, based on seven fundamental units.
9. Meter: The SI unit of length, defined as the distance traveled by light in a vacuum in 1/299,792,458 of a second.
10. Kilogram: The SI unit of mass, defined as the mass of the international prototype of the kilogram (a platinum-iridium cylinder) or, more recently, in terms of the Planck constant.
11. Second: The SI unit of time, defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the cesium-133 atom.
12. Ampere: The SI unit of electric current, defined as the flow of one coulomb of charge per second.
13. Kelvin: The SI unit of temperature, defined as 1/273.16 of the thermodynamic temperature of the triple point of water.
14. Mole: The SI unit of the amount of substance, defined as the amount containing as many particles as there are atoms in 0.012 kg of carbon-12.
15. Candela: The SI unit of luminous intensity, defined as the intensity in a given direction of a source emitting monochromatic radiation of frequency 540 × 10¹² Hz with a radiant intensity of 1/683 watt per steradian.
16. Dimension: The expression of a physical quantity in terms of fundamental quantities (e.g., length [L], mass [M], time [T]).
17. Dimensional Analysis: A method to check the correctness of physical equations or derive relationships by analyzing the dimensions of quantities involved.
18. Precision: The degree of consistency or repeatability of a measurement, indicating how close repeated measurements are to each other.
19. Accuracy: The degree to which a measurement agrees with the true or accepted value of the quantity being measured.
20. Significant Figures: The digits in a number that are reliable and contribute to its precision, including all certain digits plus one uncertain digit.
21. Error: The difference between a measured value and the true value of a quantity.
22. Systematic Error: An error that consistently affects measurements in the same way, often due to faulty equipment or calibration (e.g., a ruler with incorrect markings).
23. Random Error: An error that varies unpredictably in measurements, often due to environmental factors or limitations in measurement technique.
24. Least Count: The smallest division or value that a measuring instrument can accurately read (e.g., 1 mm for a typical ruler).
25. Scientific Notation: A method of expressing numbers as a product of a coefficient (between 1 and 10) and a power of 10 (e.g., 3000 = 3 × 10³).

These definitions cover the essential concepts from Chapter 1, focusing on measurements, units, and related terms as per the FBISE syllabus. If you need further clarification or additional definitions, please let me know!