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DIMENSIONS OF A PHYSICAL QUANTITY, , , , , what are dimensions of a physical quantity?, l/é These are the powers raised to the fundamental physical quantities to, obtain the given physical quantity., , , , , , , , , , NOTE, The fundamental quantities like mass, length and time are denoted by [M],, [L] and [T] respectively. In order to represent the dimensions of a physical quantity, in compact form, we use square bracket. The square bracket indicates that we are, referring only about dimensions and not the actual values., + imensional Formula. ;, It is the expression which represents the physical quantity in terms of, , dimensions., , , , Ex : Dimensional formula for velocity is PAST, , , , , , Dimensions of velocity are 1 in length, 0 in mass, -1 in time, , Dimensional Equation., It is an equation which shows the relation between physical quantity and its, , dimensional formula., , Ex:- [Velocity] = [M°L'T’], , , , , , , , Find the dimensions of gravitational constant (G), According to the Newton’s law of gravitation, , , , , , , , , Foc M2 oes Gm,m,, d2, ce Fd? = mad? Ee kg ms? m?, mm mym kg kg, , kqimeasce— (Ge [Mult, , , , The dimensions of the gravitational constant are 3 in length, -1 in mass, and -2 in time.