Electrical current flows through a circuit when a voltage source is applied to the circuit. Ohm's Law explains that the amount of current that flows through the circuit depends greatly upon the circuit's resistance; for example, a circuit with high resistance will allow less current to pass through than a circuit with low resistance. Therefore, controlling a circuit's resistance is a key factor in limiting the amount of current through a circuit.
Things You'll Need
- 6-volt lantern battery
- Electrical pliers
- Electrical wire
- Two 1-kiloohm resistors
- Digital multimeter
Cut two lengths of wire, and strip 1/2 inch of insulation from the ends of each wire segment.
Connect one end of the first wire to the positive battery terminal. Connect one end of the second wire to the negative battery terminal.
Twist one of the leads from the first resistor together with the loose end of the first wire.
Turn on the multimeter and set the measurement scale to "Amps DC." Place the red multimeter probe on the loose lead of the first resistor. Place the black multimeter probe on the loose end of the second wire. Check the multimeter display; it should show that approximately 6 milliamps of current are flowing through the circuit.
Remove the multimeter probes from the circuit. Twist one of the leads from the second resistor together with the loose end of the second wire. Place the red multimeter probe on the loose lead of the first resistor. Place the black multimeter probe on the free lead from the second resistor. Check the multimeter display; it should show that approximately three milliamps of current are flowing through the circuit.
Tips & Warnings
- The formula for calculating how much current is flowing through a circuit is expressed as V=I x R, where "V" represents voltage, "I" represents current, and "R" represents resistance.
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