When connecting the positive and negative poles of a battery directly, an excessive amount of current flows, potentially damaging the battery. To control this electrical flow, we introduce the concept of resistance.

Resistance serves as a restriction to the current flowing through a circuit. Each component in a circuit possesses some degree of resistance, including the wires themselves, although their resistance is typically very minimal. The unit used to measure resistance is called the ohm, denoted by the symbol Ω.

Specifically, 1 ohm is defined as 1 volt divided by 1 ampere:

1 Ω = 1 V / 1 A

This fundamental relationship is known as Ohm’s law: R = V / I, where R represents resistance, V represents voltage, and I represents current. From this equation, we can derive the following relationships:

  • V = R * I
  • I = V / R

A resistor is a component designed to provide a predetermined amount of resistance. Various resistor values exist, with common examples including 220Ω, 1kΩ, 4.7kΩ, and 10kΩ.

By applying Ohm’s law, we can calculate the current flowing through a circuit given the battery voltage and the resistance provided by the circuit components. For example, if a battery provides a voltage of 5V and the circuit contains a 1kΩ resistor, the current flowing would be 5mA.

Tags: electronics, resistance, Ohm’s law, resistor, circuit components, voltage, current