What is dimension of physical quantities ? Explain by using suitable example.
Any physical quantity can be represented by using dimension.
Any physical quantity can be represented as combination of $7$ base (fundamental) quantity.
Its symbol are as follows :
Mass : $M$
Length : $\mathrm{L}$
Time : $T$
Electric current : $A$
Thermodynamics temperature: $\mathrm{K}$
Luminous Intensity : $cd$
Quantity of matter : $mol$
Dimension : Power or exponent to which base quantity is raised to is called dimension of that quantity.
$\text { Example : Volume } =l \times b \times h$
$=m \times m \times m$
$=m^{3}$
$=l^{3}$
In volume dimension of length is $3$ where as dimension of mass and time is zero.
$\text { Example : Force }=\mathrm{F} =m a$
$=\operatorname{mass} \times \text { acceleration }$
$=\mathrm{M}^{1} \times \mathrm{L}^{1} \mathrm{T}^{-2}$
Consider a simple pendulum, having a bob attached to a string, that oscillates under the action of the force of gravity. Suppose that the period of oscillation of the simple pendulum depends on its length $(l)$, mass of the bob $(m)$ and acceleration due to gravity $(g)$. Derive the expression for its time period using method of dimensions.
With the usual notations, the following equation ${S_t} = u + \frac{1}{2}a(2t - 1)$ is
Given that $v$ is the speed, $r$ is radius and $g$ is acceleration due to gravity. Which of the following is dimensionless?
The time dependence of a physical quantity $P$ is given by $P\, = \,{P_0}\,{e^{ - \alpha {t^2}}}$ where $\alpha $ is a constant and $t$ is the time then constant $\alpha $ is
Inductance $L$ can be dimensionally represented as