An audio amplifier, represented by the ac source and resistor in the figure, delivers to the speaker alternating voltage at audio frequencies.

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An audio amplifier, represented by the ac source and resistor in the figure, delivers to the speaker alternating voltage at audio frequencies. If the source voltage has an amplitude of 12.0 V, R = 8.60 image , and the speaker is equivalent to a resistance of 10.4 image, what is the time-averaged power is transferred to it? 
 W

image
asked Mar 19, 2012 in Physics by Gummmys ~Expert~ (1,105 points)
    

1 Answer

+4 votes
 
Best answer

The voltage given is the Max Voltage.

First find the total resistance, which is simply

R total = R1 + R2    (*where R1 = 8.6  image , R2 (speaker)  = 10.4 image)

Next calculate the Max Current.

Max Current = Max Voltage / R total

Now convert this to Rms Current:

Rms Current = Max Current / 2

Now you can calculate the Power in the speaker:

Power = Irms^2 * R2    (*where Irms = Rms Current)

answered Mar 23, 2012 by Roar3215 ~Expert~ (1,318 points)
selected Mar 24, 2012 by Gummmys



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