Electric tension,potential difference and voltage (colloquial term) refer to the same scalar physical quantity, which is measured in volts. The electrical voltage is defined as the electrical potential energy stored per unit of electric charge. For example, when an electrical charge of 1.0 C is placed in a 10 V region, it acquires an electrical potential energy of 10 J. Thus, when two points meet at different electrical voltages, we say that there is a differenceinpotential.
Lookalso: Electrical circuits – resistors, switches, capacitors, generators etc.
What is electrical voltage?
electrical voltage is the amount of energy stored in each coulomb ofchargeelectric, when it is in regions where there is a electric field not null. In these conditions, when released, the loads can start to move, due to the emergence of a electric force about them. Positive charges move towards the potentialselectricmorelow, while the negative charges tend to move towards the potentialselectrictaller.
When we plug a household appliance into the socket, we are applying a differenceinpotential about the electric circuits of this appliance, causing electrical charges (in this case, electrons) to travel through it. Usually these circuits are made of a materialconductor (usually copper).
This movement of loads depends on the environment in which the loads are located. We call this displacement of loads, which results from a differenceinpotential, in electric current. The intensity of this electric current depends directly on the potential difference, as well as on the electrical resistance of the way it moves.
Lookalso: Conductors and insulators - electrical properties of materials
Electrical Voltage Formula
The electrical voltage formula relates electrical potential energy to electrical charge. Watch:
U – electrical voltage (V)
ANDP – electrical potential energy (J)
what – electric charge (C)
Below we present the formula that relates the electric voltage with the electric field. Watch:
AND – electric field (N/C)
d – distance (m)
In addition to the two formulas above, we have the formula that relates electrical voltage to resistance and electrical current, known as 1st law of Ohm.
R – Electrical resistance (Ω)
i – electric current (A)
Lookalso:Magnetism – what is it for and examples
Solved Exercises on Electrical Voltage
Question 1 — Determine the electrical voltage to which a 1.0 mC charge is subjected, knowing that its electrical potential energy is equal to 1.0 J.
a) 100V
b) 0.001 V
c) 1000V
d) 0.1V
Resolution:
To solve the exercise, we will use the formula that relates voltage to electrical potential energy and electrical charge.
Based on the above calculation, we find that the electrical voltage across the load is 1000V. Thus, the correct alternative is the letter C.
Question 2 — An electric charge is placed 2.0 m from the origin of a uniform electric field of 200 N/m. Determine the electrical voltage to which this load is subjected.
a) 4.0 V
b) 40 V
c) 0.4V
d) 400V
Resolution:
To answer this question, it is necessary to relate the voltage to the electric field. Watch:
Through the above calculation, we saw that the electrical voltage in question is 400 V, so the correct alternative is the letter D.
Question 3 — An electrical resistance of 20 Ω is carried by an electrical current of 2 mA. In this case, the electrical voltage across the terminals of this resistance is equal to:
a) 20 mV
b) 40 mV
c) 50 mV
d) 15 mV
Resolution:
Through Ohm's law, it is possible to calculate the electrical voltage between the resistor terminals.
Based on the obtained result, we realize that the correct answer is the letter B.
By Rafael Hellerbrock
Physics teacher
Source: Brazil School - https://brasilescola.uol.com.br/fisica/tensao-eletrica.htm
