A Google Pixel 7 has a 4355 mAH battery. (1mAH = 1 mA x Hour, meaning that a 1mAH device is capable of running a 1mA current for 1 hour.)
A) What is the total charge that the Google Pixel 7 battery is capable of running between its terminals?
B) How many elementary charges is it?
C) Based on A), what is the amount of electric energy stored in the battery if its emf (potential difference between the terminals) is 3.85 V? Assume that the emf does not change as the battery gets depleted.
D) The electric current running in the phone will depend on the phone's usage (Wi-Fi will require more current, etc). Let's say that at this instant, the current is 300 mA. What's the phone's resistance?
A) To find the total charge the Google Pixel 7 battery is capable of running between its terminals, we need to convert the battery capacity from mAH to coulombs.
1 mAH = 3.6 coulombs (since 1 mAH = 1 mA x 1 hour = 1 mA x 3600 s = 3.6 C)
Therefore, 4355 mAH = 4355 x 3.6 = 15678 coulombs
So, the total charge the battery is capable of running is 15678 coulombs.
B) To find how many elementary charges this is, we can use the fact that one elementary charge is approximately 1.6 x 10^-19 coulombs.
Number of elementary charges = Total charge / elementary charge
Number of elementary charges = 15678 / (1.6 x 10^-19) ≈ 9.8 x 10^20 elementary charges
Therefore, the total charge in the battery is equivalent to approximately 9.8 x 10^20 elementary charges.
C) The electric energy stored in the battery can be found using the formula:
Electric energy = Charge x emf
Electric energy = 15678 C x 3.85 V = 60303 Joules
Therefore, the amount of electric energy stored in the battery is 60303 Joules.
D) The phone's resistance can be calculated using Ohm's Law:
Resistance = Voltage / Current
Resistance = 3.85 V / 0.3 A = 12.83 ohms
Therefore, the phone's resistance is approximately 12.83 ohms.