Question 10 0 / 6 points You use your smart phone so much that the battery can't last an entire day. You decide to get an external power bank. Power banks use internal batteries with a total voltage greater than the 5 V output required by USB. This is required as your phone needs a stable 5 V power source. If we were to use a 5 V battery, the voltage would drop as the battery discharges and would eventually be too low to charge your phone. Power banks use a power regulator to lower the cell voltage to a stable 5 V to charge your phone. Regulators differ in price and efficiency and therefore affect the actual available energy. The wasted energy is given off as heat. Two options are available for you to purchase : Two options are available for you to purchase : Power Bank A Power Bank B Stated cell capacity 5000 mAh 9000 mAh Energy capacity at 6.4 V battery 64.0KJ 57.6 KJ voltage Power Regulator Linear Switching Power Regulator 0.78 0.96 Efficiency Price 25 27 a) Assuming it was possible to extract every single joule from the batteries, how many joules would Bank A supply? (2 points) bj Assuming it was possible to extract every single joule from the batteries, how many joules would Bank B supply? (2 points) c) Which power bank would be the hottest after having charged your phone? Why? (1 point) d) Which power bank is the most sustainable? Why? (1 point)