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Direct Current (DC)
Current can flow forwards or backwards through a conductor. When it only flows in one direction it is know as direct current (DC). When if flows in both directions it is know as alternating current AC, which we will talk about later. When talking about DC there are some key properties that are very important to understand and remember.
- Voltage (V or E) is the electrical pressure or force or potential voltage drop.
- Current (I) is the quantity of electron passing through a point measured in units of Ampere. One amp is 6,280,000,000,000,000,000 electron passing through a point in one second.
- Resistance (R) is the degree of of which a material reduces the flow of current. Conductors are never perfect, and different conductors have varying degrees of imperfection and those differences are measured in Ohms. One volt will force one Amp through an object with a resistance of one Ohm.
- Power (P) is the work performed by an electrical current. power is record in watt and can be calculated by multiplying the voltage by the Current.
Ohm's Law
To calculate can of the above values we can use these formulas.
V = I * R
I = V / R
R = V / I
P = V * I
P = I*I*R
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