CHAPTER – 2
The length of the path traveled by light in vacuum in 1/299,792,458 of a second is known as meter.
Length is a fundamental unit used for measurements of length, distance and height. It is equal to the distance between two marks on a Platinum-Iridium bar kept at 0 C in International Bureau of Weight and Measurements (IBWM) near Paris.
The mass of a Platinum-Iridium cylinder kept at 0 C in International Bureau of Weight and Measurements (IBWM) near Paris is considered to be 1 kilogram.
Kilogram is a fundamental unit used for measurements of mass.
It is equal to the duration of 9,192,631,770 periods of radiation of Cesium-133 in ground state.
The international system of units is based on seven independent units known as Fundamental or Basic Units. These are given below:
1. Meter (m): length, distance, height (l)
2. Kilogram (kg): mass (m)
3. Second (s): time (t)
4. Ampere (A): electric current (I)
5. Kelvin (K): temperature (T)
6. Mole (mol): amount of substance (n)
7. Candela (cd): luminous intensity (Iv)
The units that require two or more basic measurements of same units or different fundamental units for its definition are called derived units.
1. Square meter (m2): area (A)
2. Cubic meter (m3): volume (V)
3. Hertz (Hz): frequency (v)
4. Kilograms per cubic meter (kg/m3): mass density (p)
5. Meter per second m/s: speed velocity (V)
6. Radians per second (rad/s): angular velocity (w)
7. Meters per second square (m/s2): acceleration (a)
8. Newton (N) (kg.m/s2): force (F)
9. Pascal (Pa) (N/m2): pressure (P)
10. Joule (J)(N.m): work (W), energy(E), quantity of heat (q)
11. Watt (W) (J/s): power (P)
12. Coulomb (C) (A.s): quantity of electric charge (Q)
13. Volt (V) (W/A): potential difference (V), electromotive force (E)
14. Ohm (Omega): electric resistance (R)
15. Farad (F)(A.s/V): capacitance (C)
16. Weber (Wb)(V.s):...