Voltage. Voltage = Energy. Voltage = energy. To make a light bulb light up, you need to supply energy. Where does this energy come from? That’s right, a battery (or the house current if the lamp is plugged in). We will focus on the battery situation, though. Role of a battery.
Voltage = Energy
The role of the battery is to:
1. Supply the energy to do WORK upon the charge to move it.
The little men (charges) leave the battery at the positive end. They are carrying full beakers of energy. The energy is used up to light the bulb. The charges with empty beakers return to the negative end of the battery where they climb the stairs (pumped up) and pick up more energy.
1. Moving an electron within an electric field would change the ____ the electron.
A. mass of B. amount of charge on C. potential energy of
2. If an electrical circuit were analogous to a water circuit at a water park, then the battery voltage would be comparable to _____.
D. The battery establishes an electric potential difference across the two ends of the external circuit and thus causes the charge to flow. The battery voltage is the numerical value of this electric potential difference. In an analogous manner, it is the difference in water pressure between the top of the water slide and the bottom of the water slide that the water pump creates. This difference in water pressure causes water to flow down the slide. Because of the similarity between electric potential difference in an electric circuit and water pressure in a water park, the quantity electric potential difference is sometimes referred to as electric pressure.
3. If the electrical circuit in your iPod were analogous to a water circuit at a water park, then the battery would be comparable to ____.
C. The battery in an electric circuit supplies the energy to pump the charge from its low energy terminal to the high energy terminal, thus providing a means by which the charge can flow. In an analogous manner, a water pump in a water park supplies the energy to pump the water from the low energy position to the high energy position. Because of the similarity between the battery in an electric circuit and a water pump in a water park, the battery is sometimes referred to as a charge pump.
4. Which of the following is true about the electrical circuit in a flashlight?
E. As emphasized before, the battery supplies the energy to move the charge through the battery, thus establishing and maintaining an electric potential difference. The battery does not supply electrons nor protons to the circuit; those are already present in the atoms of the conducting material. In fact, there would be no need to even supply charge at all since charge does not get used up in an electric circuit; only energy is used up in an electric circuit.
5. If a battery provides a relatively high voltage, it can:
B. The electric potential difference or voltage of a battery is the potential energy difference across its terminals for every Coulomb of charge. A high voltage battery maximizes this ratio of energy/charge by doing a lot of work on each charge it encounters.