Answer:
I = 0.11 A
Explanation:
- In an electric circuit, the power delivered to a load, is just the product of the potential difference between the load terminals, times the current flowing through it, as follows:
- In this case, the power is the one consumed by the cell phone = 390 mW, and the voltage the one produced by the internal energy of the battery, 3.5 V, neglecting the voltage loss at the internal resistance of the battery.
- So, we can solve the above equation for the current I, as follows:
- The current flowing through the cell-phone circuitry is 0.11 A.