HomeworkB 10

(6 questions)

Consider the following circuit with a resistor and an inductor in series with an AC generator as shown below. The emf and frequency of the generator, as well as the values of the other components, are unknown (but greater than zero and finite).

1)  For all values of ε_m, ω, R, and L, the current through the resistor

		leads the voltage across the generator
+	X	lags the voltage across the generator
		sometimes leads, sometimes lags the voltage across the generator (depending on ω, R, and L)

2)  For all values of ε_m, ω, R, and L, the peak voltage across the resistor is __________ the peak voltage from the generator.

+	X	less than
		greater than
		sometimes less than, sometimes greater than (depending on ω, R, and L)

For the rest of the questions, assume the following values for the parameters: ε_m = 38V, R = 10 Ω, and L = 4.7 mH (10^-3H).

3)  Assuming ω = 2π x 1220Hz, what is the peak voltage across the inductor?

		12.3 V
		27.8 V
		29.8 V
+	X	36.6 V
		38 V

4)  If we were to view the generator voltage as the input, and the voltage across the inductor as the output, this circuit behaves as a

		low-pass filter
+	X	high-pass filter
		band-pass filter

5)  For what frequency (in Hz) is the RMS output voltage (across the inductor) exactly half of the RMS input voltage (from the generator)?

+	X	196 Hz
		339 Hz
		There is no frequency for which the RMS output voltage is exactly half of the RMS generator voltage.

6)  If you were to add a 200 µF (10^-6F) capacitor in series with the resistor and inductor in this circuit, and drive the circuit at ω = 2π x 1220Hz,

+	X	the impedance of the circuit would decrease.
		the impedance of the circuit would remain the same.
		the impedance of the circuit would increase.