Conversion factor

Conversion of length

  • 1 centimetre = 10-2 metre
  • 1 millimetre = 10-3metre
  • 1 micrometre = 10-6metre
  • 1 nanometre = 10-9 metre
  • 1 angstrom= 10-10 metre
  • 1 fermi = 10-15 metre
  • 1 kilometre = 103 metre
  • 1 austronomical unit = 1AU=1.496 × 1011 metre
  • 1 light year = 1 ly = 9.461 ×1015metre
  • 1 mile = 1.609 ×103 metre
  • 1 yard = 0.9144 metre
  • 1 inch = 0.0254 metre

Conversion of time

  • 1 mili second= 10-3 second
  • 1 micro second = 10-6 second
  • 1 neno second = 10-9 second
  • 1 hour = 60 minute = 3600 second
  • 1 day = 24 hours =86400 second
  • 1 year = 365 day = 3.156× 107 second
  • 1 sec = 10-8second

Conversion of mass

  • 1 gram = 10 -3 kg
  • 1 quintal = 100 kg
  • 1 tonne = 1000 kg
  • 1 slug = 14.59 kg
  • 1 Chandersekhar limit = 1.4 × mass of sun = 2.8 × 1030 kg
  • 1 atomic mass unit = 1u = 1.66×10-10

What is the dimensional formula ?

The dimensional formula of the physical quantity is an expression which shows how and which of the base quantities represent the dimensions of a physical quantity.

For example [ M0L2T0 ] is the dimensional formula of velocity. similarly, [ M0L3T0 ] is the dimensional formula of volume.

Dimensional formula of all important physical quantities.

Dimensional formula of major physical quantities e.g. area, volume, velocity, acceleration, force, momentum, impulse, work, energy, power, surface tension etc. are following:

Physical quantity Dimensional formula
Acceleration M0L1T-2
Acceleration due to gravity M0L1T-2
Angle M0L0T0
Angular acceleration M0L0T-2
Angular displacement M0L0T0
Angular frequency M0L0T-1
Angular impulse M1L2T-1
Angular momentum M1L2T-1
Angular velocity M0L0T-1
Area M0L2T0
Avogadro’s number M0L0T0
Binding energy of nucleus M1L2T-2
Boltzmann constant M1L2T-2K-1
Bulk modulus M-1L0T-2
Capacity M-1L-2T4A2
Capacitative reactance M1L2T-3A-2
Centripetal acceleration M0L1T-2
Charge M0L0T1A1
Coefficient of elasticity M1L-1T-2
Coefficient of mutual inductance M1L2T-2A-2
Coefficient of self inductance M1L2T-2A-2
Conductivity M-1L-2T3A2
Critical velocity M0L1T-1
Current density M0L-2T0A1
Decay constant M0L0T-1
Density M1L-3T0
Dielectric constant M0L0T0
Efficiency M0L0T0
Electrical resistivity M1L3T-3A-2
Electric current M0L0T0A1
Electric dipole moment M0L1T1A1
Electric field M1L1T-3A-1
Electric intensity M1L1T-3A-1
Electric potential M1L2T-3A-1
Electric permittivity of free space M-1L-3T4A2
Energy M1L2T-2
Energy density M1L-1T-2
Entropy M1L2T-2K-1
Escape speed M0L1T-1
Faraday constant M0L0T1A1mol-1
Frequency M0L0T-1
Force M1L1T-2
Force constant M1L0T-2
Gas constant M1L2T-2K-1mol-1
Gravitational constant M-1L3T-2
Heat M1L2T-2
Heat capacity M1L2T-2K-1
Hubble constant M0L0T-1
Illuminance M1L0T-3
Illuminating power of source M1L2T-3
Impulse M1L1T-1
Inductance M1L2T-2A-2
Inductive reactance M1L2T-3A-3
Intensity of illumination M1L0T-3
Intensity of wave M1L0T-3
Internal energy M1L2T-2
Kinetic energy M1L2T-2
Kinematic viscosity M0L2T-1
Latent heat M0L2T-2
Linear mass density M1L-1T0
Luminance M1L0T-3
Luminosity of radiant flux M1L2T-3
Luminous efficiency M0L0T0
Luminous flux M1L2T-3
Luminous intensity M1L2T-3
Luminous power M1L2T-3
Magnification M0L0T0
Magnetic dipole moment M0L2T0A1
Magnetic induction M1T-2A-1
Magnetic intensity A1L-1
Magnetic field M1L0T-2A-1
Magnetic field strength M0L-1T0A1
Magnetic flux M1L2T-2A-1
Magnetic permeability of free space M1L1T-2A-2
Mass defect M1L0T0
Mechanical equivalent of heat M0L0T0
Moment of force M1L2T-2
Moment of inertia M1L2T0
Momentum M1L1T-1
Planck constant M1L2T-1
Pole strength M0L1T0A1
Potential energy M1L2T-2
Power M1L2T-3
Power of lens M0L-1T0
Pressure M1L-1T-2
Pressure energy M1L2T-2
Pressure gradient M1L-2T-2
Quality factor M0L0T0
Radius of gyration M0L1T0
Radiant flux M1L2T-3
Radiant intensity M1L2T-3
Radiant power M1L2T-3
Radiation pressure M1L-1T-2
Rate of flow M0L3T-1
Refractive index M0L0T0
Relative Luminosity M0L0T0
Resistance M1L2T-3A-2
Reasonant frequency M0L0T-1
Reynolds number M0L0T0
Rydberg constant M0L-1T0
Specific gravity M0L0T0
Specific heat M0L2T-2K-1
Specific resistance or resistivity M1L3T-3A-2
Specific volume M-1L3T0
Speed M0L1T-1
Stefn’s constant M1L0T-3K-4
Surface density of charge M0L-2T1A1
Surface potential M0L2T-2
Temperature M0L0T0A1
Thermal expansion coefficient M0L0K-1
Torque M1L2T-2
Trigonometric ratio M0L0T0
Velocity M0L1T-1
Velocity gradient M0L0T-1
Velocity of light in vaccum M0L1T-1
Viscosity M1L-1T-1
Volume M0L3T0
Wave number M0L-1T0
Wien’s constant M0L1T0K1
Work M1L2T-2

How many fundamental and supplementary units in SI?

In SI, there are seven base ( fundamental ) units and two supplementary units.

Base unit

Physical quantity Unit Symbol
Mass Kilogram kg
Length Metre m
Time Second s
Temperature Kelvin K
Electric current Ampere A
Luminous intensity Candela cd
Quantity of matter Mole mol

Supplementary units

Physical quantity Unit Symbol
Plane angle Radian rad
Solid angle Steradian sr