DIMENSIONAL FORMULA
Dimensional formula is an expression which shows how and which of fundamental units are required to represent the unit of physical quantity.
Example: [M⁰LT⁻¹] is the dimensional formula of speed.
DIMENSIONAL EQUATION
DIMENSIONAL EQUATION is the equation obtained by equating the physical quantity with its dimensional formula.
The dimensional equation of speed is given as , speed = [ M⁰LT⁻¹]
FOUR CATEGORIES OF PHYSICAL QUANTITIES
1.Dimensional Constants are those physical quantities which posses dimensions and have fixed value.
Examples: (i)Gravitational constant (ii) Plank's constant
2.Dimensional variables are those physical quantities which posses dimensions and do not have a fixed value.
3. Dimensionless constants
are those physical quantities which do not posses dimensions and have a fixed value.
Example (i)numerical constants such 3, 9 ( ii)π
4.Dimensionless variables are those physical quantities whi
Examples:(i) strain (ii) specific gravity
PRINCIPLE OF HOMOGENEITY OF DIMENSIONS
A given physical relation is dimensionally correct if the dimensions of various terms on either side of relation are the same.
This principle is based on the fact that two quantities of same nature only can be added up. The resulting quantity is also same nature.
USES OF DIMENSIONAL EQUATIONS
To convert A Physical quantity from one system of units to another
Consider a physical quantity whose dimensional formula MᵅLˣT*
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