Chapter 25.7, Problem 1IE

Suppose you connect a small lightbulb across a DC power supply that has an emf of 5.0 V. You then connect the bulb across a 60.0-Hz AC power supply that has an rms voltage of 5.0 V. Does the bulb dissipate more power on average when it is connected to the DC power supply or the AC power supply? Is the bulb brighter when it is connected to the DC power supply or the AC power supply? Explain.

In the AC circuit shown in Figure P32.3, R = 70.0 and the output voltage of the AC source is Vmax sin t. (a) If VR = 0.250 Vmax for the first time at t = 0.0100 s, what is the angular frequency of the source? (b) What is the next value of t for which VR = 0.250 Vmax? Figure P32.6 Problem 3 and 5.

In a purely inductive AC circuit as shown in Figure P21.15, Vmax = 100. V. (a) The maximum current is 7.50 A at 50.0 Hz. Calculate the inductance L. (b) At what angular frequency is the maximum current 2.50A? Figure p21.15

A 1.5k resistor and 30-mH inductor are connected in series, as below, across a120-V(rms)ac power source oscillating at 60-Hz frequency. (a) Find the current in the circuit. (b) Find the voltage drops across the resistor and inductor. (C) Find the impedance of the circuit. (d) Find the power dissipated in the resistor. (e) Find the power dissipated in the inductor. (1) Find the power produced by the source.

The emf of an ac source is given by v(t)=v0sint. where V0=100V and at =200rad/s . Calculate the average power output of the source if it is connected across (a) a 20F capacitor, (b) a 20-mH inductor, and (c) a 50 resistor.

The resistor in Figure P32.49 represents the midrange speaker in a three-speaker system. Assume its resistance to be constant at 8.00 . The source represents an audio amplifier producing signals of uniform amplitude Vmax = 10.0 V at all audio frequencies. The inductor and capacitor are to function as a band-pass filter with Vout/Vin=12 at 200 Hz and at 4.00 103 Hz. Determine the required values of (a) L and (b) C. Find (c) the maximum value of the ratio Vout/Vin; (d) the frequency fo at which the ratio has its maximum value; (e) the phase shift between vin and vout at 200 Hz, at fo, and at 4.00 103 Hz; and (f) the average power transferred to the speaker at 200 Hz, at f0, and at 4.00 103 Hz. (g) Recognizing that the diagram represents an RLC circuit driven by an AC source, find its quality factor. Figure P32.49

A series RLC circuit has resistance R = 50.0 and inductance L. = 0.500 H. (a) Find the circuits capacitance C if the voltage source operates at a frequency of f = 60.0 Hz and the impedance is Z = R = 50.0 . (b) What is the phase angle between the current and the voltage?

The emf of an ac source is given by v(t)=V0sint, where V0=100V and =200 . Find an expression that represents the output current of the source if it is connected across (a) a 20-pF capacitor, (b) a 20-mH inductor, and (c) a 50 resistor.