BBC Bitesize - GCSE Physics (Single Science) - Current, voltage and resistance - Revision 4
How electrical charge relates to voltage, current, and resistance. a quick way to reference the relationship between voltage, current, resistance, and power. The first, and perhaps most important, relationship between current, voltage, and resistance is called Ohm's Law, discovered by Georg Simon Ohm and. Current is the movement of charge. It can be measured in Coulombs per second. For example, the starter motor in a car lets about Coulombs per second.
This opposition to motion is more properly called resistance. The amount of current in a circuit depends on the amount of voltage available to motivate the electrons, and also the amount of resistance in the circuit to oppose electron flow.
Just like voltage, resistance is a quantity relative between two points. Volt, Amp, and Ohm To be able to make meaningful statements about these quantities in circuits, we need to be able to describe their quantities in the same way that we might quantify mass, temperature, volume, length, or any other kind of physical quantity. Here are the standard units of measurement for electrical current, voltage, and resistance: Standardized letters like these are common in the disciplines of physics and engineering, and are internationally recognized.
Current and resistance
Each unit of measurement is named after a famous experimenter in electricity: The amp after the Frenchman Andre M. The mathematical symbol for each quantity is meaningful as well. Most direct-current DC measurements, however, being stable over time, will be symbolized with capital letters. Coulomb and Electric Charge One foundational unit of electrical measurement, often taught in the beginnings of electronics courses but used infrequently afterwards, is the unit of the coulomb, which is a measure of electric charge proportional to the number of electrons in an imbalanced state.
One coulomb of charge is equal to 6,,, electrons. Cast in these terms, current is the rate of electric charge motion through a conductor.Series and Parallel Circuits Explained - Voltage Current Resistance Physics - AC vs DC & Ohm's Law
As stated before, voltage is the measure of potential energy per unit charge available to motivate electrons from one point to another. Defined in these scientific terms, 1 volt is equal to 1 joule of electric potential energy per divided by 1 coulomb of charge.
Thus, a 9 volt battery releases 9 joules of energy for every coulomb of electrons moved through a circuit. Basic Circuit Diagram of V, I and R In the above circuit, when the voltage and resistance values are given, then we can calculate the amount of current. The differences between V, I and R are discussed below. The voltage is defined as, it is the potential difference in charge between the two points on a circuit, it is also called electromotive force.
One point has more charge than another. The unit volt is termed after invented by Italian physicist Alessandro Volta. The term volt is represented by the letter V in schematics.
The measuring instrument of voltage is the voltmeter. Voltage is the source and the current is its result, it can occur without current.
Relationship and Difference Between Voltage, Current and Resistance
The voltage gets distributed over different electronic components which are connected in series in the circuit, and in parallel circuit voltage is same across all components which are connected in parallel. The current is defined as it is the rate of flow of electric charge in a circuit. The measuring instrument of the current is an ammeter.
The flow of current is same in all the components which are connected in series. And, current gets distributed when components are connected in parallel.
Ohm’s Law - How Voltage, Current, and Resistance Relate
The Resistance is defined as, it is the opposition that a substance offers to the flow of electric current. It is denoted by the letter R. The unit of resistance is the ohm, and the measuring instrument of the resistance is a multimeter. Difference between Voltage, Current and Resistance When describing the differences between the voltage, resistance and current by taking a common analogy is a water tank.
Consider a water tank at a particular height from the ground. At the bottom of this water tank there is a tube.
In this tank, charge is denoted by the amount of water, voltage is denoted by the pressure of water and the current is denoted by the flow of water.
So for this, remember these terms: The charge is water, voltage is pressure and the current is water flow.