The newest generation of smart phone uses three different batteries connected in a series simultaneously to extend battery life and generate the energy necessary to power the device. if each battery is rated at 2.4 v , what is the overall voltage provided to the phone?

7.2 V

Explanation:

The three batteries are connected in series to the terminals of the phone: it means that they are connected along the same branch, so the current flowing through them is the same.

This also means that the potential difference across the phone will be equal to the sum of the voltages provided by each battery.

Here, the voltage provided by each battery is

V = 2.4 V

So, the overall voltage will be

V = 2.4 V + 2.4 V + 2.4 V = 7.2 V