# Current voltage power and resistance relationship

### Current, Voltage and Resistance - Humane Slaughter Association

They are Power (P) or (W), measured in Watts, Voltage (V) or (E), measured in Volts, Current or Amperage (I), measured in Amps (Amperes), and Resistance (R ). Did you know that electrical current is affected by the voltage and resistance in a circuit? In this lesson, we'll use Ohm's law, which tells us. Current, Resistance, Voltage, and Power. Current Current is a measure of the flow of electric charge . This relation can be found from the formula for power.

### Ohm's Law Calculations With Power

We saw these concepts in action with the garden hose. Increasing the pressure caused the flow to increase, but getting a kink in the hose increased the resistance, which caused the flow to decrease. Using this diagram is an easy way to solve equations. The way the equation is written here, it would be easy to use Ohm's law to figure out the current if we know the voltage and the resistance.

But, what if we wanted to solve for the voltage or the resistance instead? One way to do this would be to rearrange the terms of the equation to solve for the other parameters, but there's an easier way.

The diagram above will give us the appropriate equation to solve for any unknown parameter without using any algebra.

To use this diagram, we simply cover up the parameter we're trying to find to get the proper equation. This will make more sense once we start using it, so let's do some examples.

Ohm's Law in Action Below is a simple electric circuit that we'll use to do our examples. Our voltage source is a battery that is connected to a light bulb, which provides resistance to the electric current.

To start off with, let's say our battery has a voltage of 10 volts, the light bulb has a resistance of 20 ohms, and we need to figure out the current flowing through the circuit. Using our diagram, we cover up the parameter that we're trying to find, which is current, or i, and that leaves us with the voltage, v, over the resistance, r.

In other words, to find the current, we need to divide the voltage by the resistance.

Doing the math, 10 volts divided by 20 ohms results in one half ampere of current flowing in the circuit. To find the current, divide the voltage 20 volts by the resistance 20 ohms. Next, let's increase the voltage to see what happens to the current. We'll use the same light bulb but switch to a volt battery.

**The Basics of Voltage, Current and Resistance**

Using the same equation as before, we divide 20 volts by 20 ohms and we get 1 amp of current. The formulas related to circuits are true for "Ohmic" materials, and "non-Ohmic" materials are not discussed in this course. The resistivity of an Ohmic conductor depends on the temperature of the material. One Ohm is equal to one Volt per Ampere, Resistance depends on temperature in the same way as resistivity, This formula requires R0, the resistance at a reference temperature T0.

## Current, Voltage and Resistance

A resistor is a device that is used in electric circuits, and has a certain fixed resistance. Resistors are made by choosing a piece of material with a certain resistivity, length, and area, and wrapping it in an insulator with wires leading out of each end. In circuit diagrams, it is represented with the symbol, Voltage Voltage is a difference in electric potential between two points.

A voltage source is a device used in electric circuits that has a fixed potential difference between its ends. A voltage source can be a battery, or another source of direct current with a fixed potential difference.

## Current, Resistance, Voltage, and Power

In circuit diagrams, it is represented with the symbol, If the ends of a voltage source are connected through a circuit with any number of resistors or other components, a complete circuit is formed, and current can flow from one terminal to the other.

If current is flowing, it will be the same on both terminals of the voltage source. For an ideal source, the electromotive force is equal to the voltage difference, Real sources like batteries are not ideal, and so there is some amount of internal resistance.