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How to Get Amps in a Parallel Circuit

An electric circuit can be made up of two or more current-conducting branches. When a circuit has more than one pathway for current to travel through, it is called a parallel circuit. Each circuit branch has the same potential--also known as a voltage differential--as every other branch of that circuit. Ohm's Law explains that the voltage across a circuit branch is equal to the resistance multiplied by the current of that branch. Therefore, when multiple circuit branches have the same voltage, the sum of the currents flowing through each circuit branch equal the total current--measured in amps--flowing through the circuit. To demonstrate this property of parallel electrical circuit branches, it is necessary to measure both the amount of current flowing through each branch of the circuit and the current flowing from the power source.

Things You'll Need

Electrical wire
Electrical pliers
Three digital multimeters
6-volt lantern battery
Two 1K Ohm resistors

Instructions

- 1
  Use electrical pliers to cut four six-inch pieces of wire. Strip ½-inch of insulating material from the ends of each wire.
- 2
  Attach one end of the first wire to a positive battery terminal. Twist together one end of the second wire with one end of the third wire. Attach this twisted wire pair to the negative battery terminal.
- 3
  Twist one end of the fourth wire together with one of the leads from the first resistor and with one of the leads from the second resistor.
- 4
  Turn on all three multimeters and set the measurement scale on each meter to "DC Amps." Connect the red probe on the first multimeter to the loose end of the first wire. Connect the black probe on the first multimeter to the loose end of the fourth wire.
- 5
  Connect the red probe on the second multimeter to the free lead on the first resistor. Connect the black probe on the second multimeter to the loose end of the second wire.
- 6
  Connect the red probe on the third multimeter to the free lead on the second resistor. Connect the black probe on the third multimeter to the loose end of the third wire.
- 7
  Observe the display on the first multimeter. It will show that 12 milliamps of current are flowing from the battery through the circuit. Observe the second and third multimeter displays. Each display will show that six milliamps are flowing through each circuit branch. This is equal to the total current flowing through the circuit (six milliamps times two branches equals 12 milliamps total).

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