Generally, a single battery is not enough to power some devices. In such cases, batteries can be combined in two ways: in series or in parallel.
In series, the positive terminal of one battery is connected to the negative terminal of another battery. Hence, the voltage of each battery is added to give the net voltage, which is increased because each battery boosts the electrons that enter it. The same current flows through each battery because they are connected in series.
Batteries are...

A battery is a galvanic cell that is used as a source of electrical power for specific applications. Modern batteries exist in a multitude of forms to accommodate various applications, from tiny button batteries such as those that power wristwatches to the very large batteries used to supply backup energy to municipal power grids. Some batteries are designed for single-use applications and cannot be recharged (primary cells), while others are based on conveniently reversible cell reactions that...

A conductor needs to be a component of a path that creates a closed loop or full circuit to have a continuous current flowing through it. A current starts to flow if an electric field is created inside an isolated conductor that is not part of a full circuit. The conductor quickly develops a net positive charge at one end and a net negative charge at the other. These charges generate an electric field opposite the direction of the applied electric field, which reduces the current. Eventually,...

Ionic radius is the measure used to describe the size of an ion. A cation always has fewer electrons and the same number of protons as the parent atom; it is smaller than the atom from which it is derived. For example, the covalent radius of an aluminum atom (1s22s22p63s23p1) is 118 pm, whereas the ionic radius of an Al3+ (1s22s22p6) is 68 pm. As electrons are removed from the outer valence shell, the remaining core electrons occupying smaller shells experience a greater effective nuclear...

Kirchhoff's rules quantify the current flowing through a circuit and the voltage variations around the loop in a circuit. Applying Kirchhoff's rules generates a set of linear equations that allow us to find the unknown values in circuits. These may be currents, voltages, or resistances.
When applying Kirchhoff's first rule, the junction rule, label the current in each branch and decide its direction. If the chosen direction is wrong, it will have the correct magnitude, although the...

The equivalent resistance of a combination of resistors depends on their values and how they are connected.
The simplest combinations of resistors are series and parallel connections. In a series circuit, the first resistor's output current flows into the second resistor's input; therefore, each resistor's current is the same. Thus, the equivalent resistance is the algebraic sum of the resistances. The current through the circuit can be found from Ohm's law and is equal to the...