A cylindrical resistor is made of so me material. The resistor has a rresistance of 2900 (ohms) at a temperature oof 293 K.
Note: the resistivity of the material is p0= 1.20 (ohms) and the resistor has an average temperature coefficient of ressistivity of a = -7x10*-4 K-1 both at 293 K
the resistor is then connected to an AC power supply and the power output is 22.5W with the resistor operating at 293K. What is the peak amplitude of the AC powe supply voltage?
please help i have answered the other questions but i dont get this question. is there a formula or something?
Note: the resistivity of the material is p0= 1.20 (ohms) and the resistor has an average temperature coefficient of ressistivity of a = -7x10*-4 K-1 both at 293 K
the resistor is then connected to an AC power supply and the power output is 22.5W with the resistor operating at 293K. What is the peak amplitude of the AC powe supply voltage?
please help i have answered the other questions but i dont get this question. is there a formula or something?
-
This question contains a lot of irrelevant information which makes it confusing, but excludes a vital piece of info without which the question cannot be answered !
Using the formula Pavg = (Vrms)^2/R, and assuming that the 'power' mentioned in the question is the average power calculated over a complete cycle, or an integral number of cycles, or over a time interval very long compared with a period, we can write:
Vrms = sqrt(Pavg*R) = 255.4V
Vrms is the RMS value of the AC voltage. In order to calculate the peak voltage we need to know the waveform of the AC supply, and we are not told this. If the waveform is sinusoidal, which is the case with domestic AC mains supplies, then the peak voltage is Vrms*sqrt(2) = 361V
Using the formula Pavg = (Vrms)^2/R, and assuming that the 'power' mentioned in the question is the average power calculated over a complete cycle, or an integral number of cycles, or over a time interval very long compared with a period, we can write:
Vrms = sqrt(Pavg*R) = 255.4V
Vrms is the RMS value of the AC voltage. In order to calculate the peak voltage we need to know the waveform of the AC supply, and we are not told this. If the waveform is sinusoidal, which is the case with domestic AC mains supplies, then the peak voltage is Vrms*sqrt(2) = 361V