- Submitted By: ailaf
- Date Submitted: 11/03/2010 6:08 PM
- Category: English
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CHAPTER – 2

Definitions

1. Meter

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.

2. Kilogram

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.

3. Second

It is equal to the duration of 9,192,631,770 periods of radiation of Cesium-133 in ground state.

Fundamental Units

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)

Derived Units

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):...