Electricity is transmitted through wire conductors that are either solid or stranded. These two types of wires aid in powering electric wall sockets, vehicles and appliances. Both stranded and solid wires are capable of transmitting electricity, but they have different characteristics that make them specific to particular situations and purposes.
Purpose
Solid wires are most commonly used for AC applications that require higher voltage, but stranded wires work best for lower-voltage DC applications. For instance, solid wires are found running through walls to send the highest levels of electrical current to power areas. On the other hand, stranded wires, such as extension cords, are usually connected to smaller appliances, such as lamps or toasters.
Flexibility
Stranded wire is very flexible, making it easy to bend and route through places that require current. It also works best in situations where wire is subject to vibration and extensive movement because it is sturdy while still retaining flexibility. In contrast, solid wire is more stiff and prone to break if it is bent excessively. This is why it works well when used in applications where wires will sustain very little motion or vibration.
Size
Stranded wire has a larger diameter than solid wire. This is mainly due to the spaces between the strands and the need for more insulation to cover them. Its larger diameter is what makes it more flexible and pliable for installation and routing. Solid wire is only available in small sizes, and its reduced diameter contributes to its rigidity and makes it better for use in static applications.
Other Differences
Solid wire consists of one piece of wire, and stranded wire has several wires bundled together inside of its installation. When a wire bundle has more strands, it is more pliable and resistant to breaking, and it's also more costly. For this reason, stranded wire is more expensive to acquire than solid wire. Also, solid core wire is thicker than stranded wire. This is mainly because solid wire is exposed to direct current, which sends an electric charge through the entire wall of the wire. AC charges, which are most common in stranded wire applications, tend to flow only along the outside of a wire, allowing use of a thinner wire.