The Total solution for NCERT class 6-12
Precise measurements of physical quantities are a need ofscience. For example, to ascertain the speed of an aircraft, one must have anaccurate method to find its positions at closely separated instants of time.This was the actual motivation behind the discovery of radar in World War II.Think of different examples in modern science where precise measurements oflength, time, mass etc. are needed. Also, wherever you can, give a quantitativeidea of the precision needed.
It is indeed very true that precise measurements of physicalquantities are essential for the development of science. For example,ultra-shot laser pulses (time interval ∼ 10–15 s)are used to measure time intervals in several physical and chemical processes.
X-ray spectroscopy is used to determine the inter-atomicseparation or inter-planer spacing.
The development of mass spectrometer makes it possible to measurethe mass of atoms precisely.