Why do different batteries have different voltages?
Capacity – Batteries have different ratings for the amount of power a given battery can store. The nominal voltage of a battery depends on the chemical reaction behind it. A lead-acid car battery will output 12V. A lithium coin cell battery will output 3V.
Why is the voltage of the battery not the same as the voltage across the resistor?
As the battery forces charge through the resistor, indeed that energy is converted into heat. An ideal battery has enough power so that it can supply the current without any voltage drop. Unless Ri=0 the resulting voltage across the resistor is less than the battery voltage.
How does changing the battery voltage affect the voltage across the resistor?
For a simple series circuit (ideal battery and resistor), the voltage across the battery terminals is the same as the voltage across the resistor. If we increase the value in ohms of the resistor, the voltage across the battery terminal and the resistor remains the same.
What is the relationship between battery voltage and current?
The current in a circuit is directly proportional to the electric potential difference impressed across its ends and inversely proportional to the total resistance offered by the external circuit. The greater the battery voltage (i.e., electric potential difference), the greater the current.
Why do big and small batteries produce the same voltage?
It depends on the chemical makeup of the cell. The larger size of the battery just means that there’s more fuel in the tank, so to speak. The great range of voltaic cells produce a voltage of just over a volt. This is how the volt was picked, in any case.
How is the voltage of a car battery determined?
Voltage is determined by the different chemical reactions used in different designs. For example, a small alkaline ‘C’ cell used in a flashlight puts out about 1.5v. Each of the six cells in your lead-acid car battery put out about 2v for a total of 12v.
How are two identical cells connected in parallel?
You’ve answered your question yourself. They have the same open-circuit voltage. Clearly, two identical cells connected in parallel provide the same open-circuit voltage as one of the cells but two cells in parallel can provide twice the short-circuit current of the single cell. Battery is not an ideal voltage source**.
How is the voltage of a cell determined?
A cell is a single electrochemical device, consisting of two plates and an electrolyte – the voltage of the cell is determined by the materials used. Every set of materials has a electrochemical voltage associated with it. THe voltage is determined by the type of material, not the size or quantity.