If a short circuit occurs-or even if too many appliances get hooked up to one wire so that too much current flows-the wire in the fuse heats up quickly and melts, breaking the circuit and preventing a fire from starting. The current that goes to appliances must also pass through this strip of wire. 2PCS 14 AWG Alligator Clips Test Leads Dual Ended Crocodile Heavy Duty Wire Cable with Insulators Clips Test Flexible Copper Cable for Electrical Testing 6.6ft / 2m Wire Length 4. A fuse contains a thin strip of wire, somewhat like the thin steel wire in our experiment. In this situation, a very large current can occur, producing a lot of heat and a fire hazard.Īlthough houses today often have circuit breakers instead of fuses, fuses are still around. A short circuit occurs when the current finds a way to bypass the appliance on a path that has little or no resistance-for example, where frayed insulation bares a wire and allows it to touch the frame of the appliance, so the current can flow straight to the ground. Every such appliance has a certain amount of resistance to the current flow, which keeps the current from reaching very large values. In a normal electric circuit, an electric current powers an appliance, such as a refrigerator or TV. At 3 feet long, these right-angle test leads feature heavy-duty alligator clips to attach to wires and other conductors.

Eventually, when you make the steel wire short enough, so much current flows that it melts the wire. Klein Tools Test Leads with Heavy-Duty Alligator Clips are intended for use as replacement test leads for meters that have banana-type input jacks. Because the same voltage is applied across a lower resistance, more current flows, and the wire heats up more. As you move the clip closer to the battery, the resistance of the steel wire decreases. When you connect the clip to the steel wire, the voltage of the battery pushes electrons through the circuit against the resistance of the steel wire, causing the steel wire to heat up. Thus most of the resistance of the circuit is in the steel wire. The thin steel wire is a good conductor of electricity, but not as good as the copper wire, which is deliberately chosen to have very low resistance.

Wire with alligator clips