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AC – Part 3. Today – Continue with AC Problems Some new material from the chapter Quiz on Friday; Exams will be returned and reviewed. There is a new Mastering Physics Assignment that finishes the chapter. Continue with chapter. Monday – Electromagnetic Waves – Putting it all together.
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Today – Continue with AC • Problems • Some new material from the chapter • Quiz on Friday; Exams will be returned and reviewed. • There is a new Mastering Physics Assignment that finishes the chapter. • Continue with chapter. • Monday – Electromagnetic Waves – Putting it all together. what does the future hold for us?
An AC source with ΔVmax = 125 V and f = 25.0 Hz is connected between points a and d in the figure. Calculate the maximum voltages between the following points: (a) a and b 62.8 V(b) b and c 45.6 V(c) c and d 154 V(d) b and d 108 V
lets talk averages What is the time average of this sine (AC) signal? ZERO!
Look at the square; what is its average? ALWAYS POSITIVE
What is the AMPLITUDE of the voltage that comes into your home?? 120V is the ‘rms’ value. (Did you know that??)
what do we pay for? Energy !
The Math ….. } Average = ZERO
The power of a certain CD player operating at 120 Vrms is 20.0W. Assuming that the CD player behaves like a pure resistance, find • the maximum instantaneous power. • the rms current. • the resistance of this player.
A series R-L-C circuit is connected to a 120 Hzac source that has Vrms = 80.0 V. The circuit has a resistance of 80.0 Wand an impedance of 106 Wat this frequency. What average power is delivered to the circuit by the source? 106W 80.0 W f