Answer Happy

Question 3: (40 points) Many people don't realize that leaving a charger in the wall without the device attached in draws current. Chargers are transformers. Let's see how this works for a cell phone charger a) My cell phone is powered by a Lithium ion battery, which generates 3.7V DC and stores 1100 mAh of charge. How much charge (in C) is stored in the battery b) if the charger supplies 6V, 800 mA to the phone, how much current is being drawn from the wall? Now disconnect your phone, leaving the charger plugged in to the wall. c) draw a circuit diagram for the charger only. Don't forget that every wire has a finite resistance! The wall supplies 120 V 60 Hz AC. d) using the expressions for the AC voltage drop across a resistor and inductor in series, write down the voltage drop for the primary side of the charger. This equals the EMF of the wall supply. You should get something like V=1 *(effective resistance). How much power is my charger consuming while the phone is not connected?