uninit of physical quantities

Based on dimensions, physical quantity can be classified under four categori..

There are 7 physical quantities viz., Length, mass, time, temperature, electric current, luminous intensity and amount of substance. Length, mass and time are called fundamental physical quantities..

The dimensional formula of a physical quantity can be obtained by defining its relation with other physical quantities and then expressing these quantities in terms of mass [M], length [L] and time [..

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X is the sum of 2 observed quantities a and b. X = a + b Maximum absolute error in X = Maximum absolute error in a + Maximum absolute error i..

Let D a and D b be absolute errors in measurement of quantities a and b and D X be maximum possible error in X. ..

Relative error in an is n times the relative error a It can be proved that maximum relative error in X, Also, maximum percentage error in X, Maximum percentage error in X = l times maximum percentage error in a + m times maximum percentage error in b + n times maximum percentage error in c..

Order of magnitude of a quantity is the power of 10 of the number that describes the quantity..

A unit of a quantity is the standard quantity used to measure a physical quantity..

It is the term which tells about the power with which a fundamental quantity is contained in a physical quantity..