raviiisc

 Profile Answers by raviiisc 

• Apr 9th, 2011

 

The rms value arised in the following manner:

The heat dissipation with AC supply will found, then the DC supply is applied such that same heat production in resistor. That DC voltage value is said to be the rms value of the AC supply.

The Rms value came inti picture to make bridge between AC and DC supplies.

SURAJTHEGREAT

 Profile Answers by SURAJTHEGREAT Questions by SURAJTHEGREAT

• Apr 10th, 2011

 

AC values are always alternating.Hence we cannot make a precise analysis!!!!So we use RMS value.
Let us consider a bulb B.IF it is switched to position A(it is connected to ac supply).
IF switched to pos B(it is connected to dc supply).DC supply is also connected to ammeter.
 Initially it is switched to pos A(ie AC) and brightness of the filament is noted .Now switched to position B(ie DC) and rheostat is adjusted to produce same brightness.Now note the reading in the ammeter.
If the reading is 0.5amps,Then RMS value of that AC supply is 0.5A