Physical Quantities: Formulas, Dimensions and SI Units Explained

Classified in Physics

Written on October 9, 2026 in English with a size of 66.66 KB

S.No	Derived Physical Quantity	Formula	Dimensional Formula	S.I Unit of physical quantity
1.	Area	$l\times b$	[ $M^0L^2T^o$ ]	$m^2$
2.	Volume	$l\times b\times h$	[ $M^0L^3T^o$ ]	$m^3$
3.	Density	$\frac{M}{V}$	[ $M^1L^{-3}T^0$ ]	$kg/m^3$
4.	Specific Gravity	$\frac{Density of Substance}{Density of Water}$	[ $M^0L^0T^0$ ]	No units
5.	Frequency	$\frac{no of vibrations}{Time}$	[ $M^0L^0T^{-1}$ ]	hertz
6.	Angle	$\frac{Arc}{radius}$	$M^0L^oT^o$	No units
7.	Velocity	$\frac{Displacement}{time}$	$M^0L^1T^{-1}$	m/sec
8.	Speed	$\frac{Distance}{time}$	$M^0L^1T^{-1}$	m/sec
9.	Areal velocity	$\frac{Area}{time}$	$M^0L^2T^{-1}$	$m^2sec^{-1}$
10.	Acceleration	$\frac{Change in velocity }{time}$	$M^0L^1T^{-2}$	$m/sec^2$
11.	Linear momentum	$M\times V$	$M^1L^1T^{-1}$	kg m/sec
12.	Force	$mass\times acceleration$	$M^1L^1T^{-2}$	kg-m/ $sec^2$ or Newton
13.	Weight	w=mg	$M^1L^1T^{-2}$	kg-m/ $sec^2$ or Newton
14.	Moment of force/Torque/Couple	$Force\times arm$	$M^1L^2T^{-2}$	kg $m^2sec^{-2}$
15.	Impulse	$Force\times time$	$M^1L^1T^{-1}$	kg m/sec or Ns
16.	Pressure	$\frac{Force}{Area}$	$M^1L^{-1}T^{-2}$	N/ $m^2$ or Pa
17.	Work	$Force\times Distance$	$M^1L^2T^{-2}$	Nm or Joule
18.	Kinetic Energy	$\frac{1}{2} mv^2$	$M^1L^2T^{-2}$	joule
19.	Potential Energy	mgh	$M^1L^2T^{-2}$	joule
20.	Gravitational constant	$\frac{Force\times (Length)^2}{(mass)^2}$	$M^{-1}L^3T^{-2}$	$kg^{-1}m^3sec^{-2}$
21.	Gravitational field strength	$\frac{Force}{mass}$	$M^0L^1T^{-2}$	$N kg^{-1}$
22.	Gravitational Potential	$\frac{Work}{mass}$	$M^0L^2T^{-2}$	$J kg^{-1}$
23.	Force constant (k)	$\frac{F}{L}$	$M^1L^0T^{-2}$	$N m^{-1}$
24.	Power	$\frac{Work}{time}$	$M^1L^2T^{-3}$	W or J/sec
25.	Moment of Inertia ( I )	$Mass\times Distance^2$	$M^1L^2T^{0}$	kg $m^2$
26.	Stress	$\frac{Force}{Area}$	$M^1L^{-1}T^{-2}$	N/ $m^2$ or Pa
27.	Strain	$\frac{Change in length}{Origional length}$	$M^0L^0T^0$	No units
28.	Modulus of Elasticity	$\frac{Stress}{Strain}$	$M^1L^{-1}T^{-2}$	N/ $m^2$ or Pa
29.	Poisson’s Ratio	σ = $\frac{Y}{2n}$ -1	$M^0L^0T^0$	No units
30.	Velocity gradient	$\frac{Change in velocity}{Distance}$	$M^0L^0T^{-1}$	$sec^{-1}$
31.	Coefficient of dynamic viscosity	$\frac{Tangential stress}{Velocity Gradient}$	$M^1L^{-1}T^{-1}$	kg $m^{-1}sec^{-1}$ (or) N-sec/$latex \m^2$ (or)pascal-sec (or)poiseuille
32.	Surface Tension	$\frac{Force}{Length}$	$M^1L^0T^{-2}$	$kg sec^2$ ,N/m
33.	Angular displacement ( $\theta$ )	$\frac{Arc}{radius}$	$M^0L^oT^o$	no Units
34.	Angular velocity(ω)	$\frac{Angular displacement}{Time}$	$M^0L^oT^{-1}$	rad/sec
35.	Angular acceleration(α)	$\frac{Change in angular velocity}{Time}$	$M^0L^oT^{-2}$	rad/ $sec^{-2}$
36.	Angular momentum	Iω	$ML^2T^{-1}$	$kg-m^2 sec^{-1}$
37.	Angular Impulse	Iω	$ML^2T^{-1}$	$kg-m^2 sec^{-1}$
38.	Temperature		$\theta$ or K	kelvin or degree Celsius
39.	Coefficient of linear expansion(α)	$\frac{l_2-l_1}{l_1\times Temp(t_2-t_1)}$	$M^0L^0T^0K^{-1}$	/kelvin
40.	Specific heat	$\frac{Energy}{Mass\times Temp}$	$M^0L^2T^{-2}K^{-1}$
41.	Latent heat	$\frac{Energy}{Mass}$	$M^0L^2T^{-2}$	$joule-kg^{-1}$
42.	Entropy	$\frac{Q}\theta$	$M^1L^2T^{-2}K^{-1}$	$J K^{-1}$
43.	Thermal capacity	$\frac{H}\theta$	$M^1L^2T^{-2}K^{-1}$	$J K^{-1}$
44.	Gas constant	$\frac{PV}{m T}$	$M^0L^2T^{-2}K^{-1}$	$joule-K^{-1}$
45.	Coefficient of thermal conductivity	$\frac{Qd}{A(\theta_2-\Theta_1)t}$	$M^1L^1T^{-3}K^{-1}$	$W m^{-1}K^{-1}$
46.	Pole strength	$Ampere\times meter$	$M^0L^1T^0I$	Am
47.	Magnetic Moment		$M^0L^2T^0I^1$	$Amp-m^2$
48.	Magnetic flux $\phi$		$ML^2T^{-2}I^{-1}$	weber ; $T-m^{2}$ ;J/Amp
49.	Magnetic field, magnetic flux density (B)		$MT^{-2}I^{-1}$	Tesla; $J/A-m^{2}$
50.	Permeability of free space	$\frac{\mu}{\mu_r}$	$MLT^{-2}I^{-2}$	$NA^{-2}$
51.	Magnetic susceptibility, also called volumetric or bulk susceptibility χm	χm = μr − 1	$M^0L^oT^o$	no units
52.	Electric Charge	$I\times T$	$M^0L^0T^1I^1$	Amp sec, coul
53.	Electric potential	$\frac{Work}{Charge}$	$M^1L^2T^{-3}I^{-1}$	Volt
54.	E.M.F	$\frac{Work}{Charge}$	$M^1L^2T^{-3}I^{-1}$	Volt
55.	Electric Capacity	$\frac{q}{V}$	$M^{-1}L^{-2}T^4I^2$	Farad
56.	Electric Resistance	$\frac{V}{i}$	$M^1L^2T^{-3}I^{-2}$	Ohm (Ω) or volt/amp
57.	Resistivity $\rho$	$\frac{R A}{L}$	$M^1L^3T^{-3}I^{-1}$	Ohm m (Ω-m)
58.	Conductivity $\sigma$	1/ $\rho$	$M^{-1}L^{-3}T^3I$	Siemens/m
59.	Permittivity $\varepsilon$	$\varepsilon = \varepsilon_r \varepsilon_0 = (1+\chi)\varepsilon_0$	$M^{-1}L^{-3}T^4I^2$	farad/m
60.	Electric conductance	$\frac{1}{R}$	$M^{-1}L^{-2}T^3I^2$	Siemens (or) mhos
61.	Electric power	$V\times I$	$M^1L^2T^{-3}I^{-1}$	Watt
62.	Electrical Impedance (Z)	$\frac{V}{i}$	$M^1L^2T^{-3}I^{-2}$	Ohm (Ω) or volt/amp
63.	Electrical admittance	1/Z (Reciprocal of electric impedance)	$M^{-1}L^{-2}T^3I^3$	Siemens (or) mhos
64.	Self Inductance(L)	$\displaystyle v=L\frac{di}{dt}$	$ML^2T^{-2}I{-2}$	weber/amp or Henry
65.	Boltzmann’s constant	$\frac{Energy}{Temp}$	$M^1L^2T^{-2}K^{-1}$	J/kelvin
66.	Stefan’s constant	$\frac{E}{At \theta^4}$	$M^1L^0T^{-3}K^{-4}$	$W m^{-2}K^{-4}$
67.	Co-efficient of friction $\mu$	$\mu$ = $\frac{F}{N}$ , N=Normal reaction	dimensionless scalar	no units
68.	Dielectric constant $\varepsilon_r$	It is also called relative permittivity	dimensionless	no units
69.	Planck’s constant	$E=h\nu$	$ML^2T^{-1}$	J.sec (or) eV.sec
70.	Refractive index	μ	$M^0L^oT^o$	no units
71.	Focal length(f)	Distance between center of the lens (mirror) to its focus	L	meter
72.	Power of a lens (P)	The reciprocal of the focal length of a lens in meters is called power of a lens; P=1/f	$L^{-1}$	diopters
73.	Wave number	No. of waves/distance	$L^{-1}$	$m^{-1}$
74.	Wave length	Length of a wave	L	meter