Learning Outcomes
Students should be able to:
- demonstrate the meaning, importance and applications of precision in the measurements
- understand the meaning and importance of significant figures in measurements
- explain the meaning of dimensions of a physical quantity
- workout the dimensions of derived physical quantities applicable to this syllabus
- apply dimensional analysis method to check the homogeneity of physical equations
The branch of science which deals with the study of natural phenomena is called physics. To understand physics, we must be able to connect our theoretical description of nature with experimental observations. Such connection is made through quantitative measurements. In physics, we have to deal with a large number of physical quantities like, length, mass, time, velocity, force, pressure, density etc. These quantities can give clear understanding only if we can measure them directly or indirectly and express our conclusions in terms of these measurements. Such quantities are called physical quantities. Measurement is required to know the physical quantity quantitatively. Due to this reason, physics is sometimes called the science of measurement.
The process of comparing an unknown physical quantity with a known fixed quantity is called the measurement. The quantity used as a standard of measurement is called the unit. Physical quantity is expressed quantitatively as the multiple of the unit taken.
1.1 Precision and Significant Figures
1.1.1 Precision and Accuracy
Accuracy and precision are important for correct measurements in science. Measurement of any physical quantity is never absolutely correct. Precision refers to how closely individual measurements agree with each other. Thus precision of measured values refers to how close the agreement is between repeated measurements. So precision is the degree of exactness and gives the limitation of the measuring instrument.
Tags:
Physical Quantities