AC/DC Currents
There are two types of currents, Alternate Currents and Direct Currents. Alternating Currents (AC) is a current that flows back and forth or alternates, an example of this is a wall outlet. The other current is the Direct Current (DC), this current flows in one direction, an example of this would be a battery.
Voltage
Voltage is the electric potential difference between two points. It is the potential for an electric field to cause an electric current to flow. Voltage is measured in volts and given the symbol V. Voltage can be measured using a voltmeter.
Voltage Calculation
When we know the current and resistance, we can calculate the voltage.
The voltage V in volts (V) is equal to the to the current I in amps (A) times the resistance R in ohms (Ω):
Example: What is the voltage of a battery if it produces a current of .75 amps in a 12Ω resistor?
V = IR V = (.75A)(12Ω) = 9V
The voltage V in volts (V) is equal to the to the current I in amps (A) times the resistance R in ohms (Ω):
Example: What is the voltage of a battery if it produces a current of .75 amps in a 12Ω resistor?
V = IR V = (.75A)(12Ω) = 9V
Electric Power
Electric Power is the rate at which electrical energy is transferred. The unit for power is the watt (w). When there is a current (I) in a circuit as a result of a voltage (V), the electric power (p) is delivered to the circuit.
P=(I)(V)
Example: What is the power of an appliance that draws 13a when connected to a 110v circuit?
P = (I)(V) P = (13)(110) = 1430w
P=(I)(V)
Example: What is the power of an appliance that draws 13a when connected to a 110v circuit?
P = (I)(V) P = (13)(110) = 1430w