Utilization of Electrical Power | Effective or RMS value | Definition | Image

Utilization of Electrical Power:

~ The electric power has a number of applications or utilization areas. It is used in domestic as well as industrial applications.
~ Following are some of the applications of electrical power:
1.  Domestic applications such as lighting, fans, heaters, irons, water boilers, washing machine, TV, refrigerators etc.
2. AC and DC motor drives.
3. Machine tool applications. (lathe machine, drillingl machine, milling machine etc.)
4. Electrically operated vehicles, trains, cars. 5. Induction heating and dielectric heating. 6. Electric welding (Resistance welding).
7. Electrometallurgical systems.
8. Electroagro systems (Pumps etc).
9. Electroplating.
10. illumination (lighting applications).
These are some of important areas of applications. There are many more.

Effective or R. M. S. Value :

~ The ac current value changes continuously with uime, whereas the direct current remans constant with respect to time.
~ In order to relate these currents we consider the effect which is common to both the types of currents.
~ The common effect is the production of heat due to current flowing through a resistor. Hence this effect is used for companng the ac and dc currents.
~ The definition and other important points related to the effective or R.M.S. (root mean square) value are as follows.
Note : RMS value exists for any AC quantity such as voltage, current etc.

Definition:

The effective or RMS value of an ac current is equal to thei steady state or DC current that is required to produce the samei amount of heat as produced by the ac current provided that thei resistance and time for which these currents tlow are identical.

~ All the ac currents or voltages are expressed as RMS values unless clearly specified otherwise.
~ RMS value of ac current is denoted by I and RMS voltage is denoted by Vms. i
RMS value of a sinusoidal waveform (sine or cosine) is equal to 0.707 times its peak value.
I= 0.707 Im
~ RMS value is called as the heat producing component of aci current. i
~ Amount of light produced by a lamp or the amount of heat produced by an iron 1s proportional to the square of rms valuei of current tlowing through them.