Voltage, current and resistance

Voltage (measured in 'Volts' and indicated by the letter 'V'), current (measured in Amperes and indicated by the letter 'A') and resistance (measured in Ohms and indicated by the letter 'R') are often abstract concepts that are difficult to imagine exactly how they work. The three concepts are often confused and therefore used incorrectly. However, it is important to know exactly what these concepts mean and what the differences are. Incorrectly interpreting the concepts can lead to dangerous situations. This article explains the concepts of voltage, current and resistance with practical examples.

 

Tension

Voltage indicates the amount of electrical voltage between two connection points. Voltage is expressed in volts (V), which is abbreviated in the formula with a U. Another commonly used name for volts is voltage. The statement: "Watch out, there is current on the socket" is not correct. If there is no plug in the wall socket, there will be no current flowing. Apart from that, it is officially called a wall socket and not a socket, but that is besides the point. At that moment, there is voltage on the contacts in the wall socket. To be able to calculate voltage, you need current and resistance values.
The formula to calculate voltage is: U (voltage) = I (current) x R (resistance).

 

Current

When the circuit is closed, an electric current of electrons flows from one terminal to the other. The amount of electric charge that moves through a live wire per second is the current. The unit of current is expressed in ampere (A), which is abbreviated in the formula with an I. To calculate current, you need voltage and resistance values.
The formula to calculate current is: I (current) = U (voltage) / R (resistance).

 

Resistance

In any electrical circuit, it takes energy for electrons to move through it. The amount of energy this takes is called resistance. The lower the resistance, the easier it is for electrons to move through the conductor. Resistance is measured in ohms (Ω), which is abbreviated in the formula with an R. To calculate resistance, you need voltage and current values.
The formula to calculate resistance is: R (resistance) = U (voltage) / I (current).