In: Electrical Engineering
Ch 26
32. A power pack charging a cell phone battery has an output of 0.4 A at 5.2 V, both rms. If the power pack is plugged into a 120 V wall socket, what is the rms current? 17.3 mA
33. A neon sign transformer has a 450 Watt AC output with an rms voltage of 15kV when connected to a normal household outlet. There are 500 turns of wire in the primary cell.
a) How many turns of wire are in the secondary coil? 62,500 turns
b) When the transformer is running full power. What is the current in the secondary coil? 30 mA
c) When the transformer is running full power. What is the current in the primary coil? 3.75 A
34. A generator produces 250 kW of electric power at 7.2 kV. The current is transmitted to a remote location through wires with a total resistance of 15 W.
a) What is the power loss due to the resistance in the wires? 18 kW
b) What is the power loss if the voltage increased to 30 kV? 1 kW
35. A 20 µF capacitor is connected across an AC generator that produces a peak voltage 6 Volts. The peak current is 0.2 A. What is the oscillation frequency in Hz? 265 Hz
36. A 500 µH inductor is connected across an AC generator that produces a 3.5 V rms Voltage. What is the frequency if the peak current is 50 mA? 31.5 kHz
37. An FM radio station broadcasts at a frequency of 103.5 MHz. What inductance should be paired with a 10 pF capacitor to build a receiver circuit for this station? 236 nH