Final answer:
A resistor is an element used in electrical circuits that provides a known resistance. It is often represented by a zigzag symbol labeled R. Resistors can be made of carbon or metal oxide materials and are color-coded for easy identification.
Step-by-step explanation:
A resistor is an element used in electrical circuits that provides a known resistance. It is represented by the zigzag symbol labeled R. Resistors are made of different materials, with carbon being the most common. They come in various resistance values and are often color-coded for easy identification.
Resistances can range over multiple orders of magnitude, from 10^12 or more for ceramic insulators to as low as 10^-5 for large-diameter copper wire. Superconductors, on the other hand, have no resistance at all when at low temperatures.
It is worth noting that resistance is related to the shape of an object and the material it is made of. The resistance of a resistor can be calculated using Ohm's law, which states that resistance (R) is equal to the voltage (V) divided by the current (I).