1. A flashlight is made by drawing current from a 1.58 A · h, 1.44 V battery through a light emitting diode (LED). The LED draws a current of 36.0 mA.
(a) Determine the power delivered to the LED.
(b) Determine how many hours a fresh battery will power the flashlight.
2. A homemade capacitor is made from a sandwich of a piece of paper (9.0 in. by 15 in., 0.0033 in. thick) between two equal area sheets of aluminum foil.
(a) Calculate the capacitance of this device.
(b) What maximum potential can be put across it?
(c) How much energy can be stored in it at maximum voltage?