ELECTRIC CIRCUITS BRAINPOP



ELECTRIC CIRCUITS BRAINPOP

❖ Joseph P. of Niskayuna, NY asked, “What is an electric circuit made of?”

❖ A CIRCUIT is a way of routing electricity along a PATH.

❖ Electricity happens when ELECTRONS, the negatively-charged particles in an atom, MOVE from one place to another.

❖ Electricity is nearly INSTANT in the natural world – think of a bolt of LIGHTNING or when you get a shock from touching someone. Those are examples of STATIC electricity – sort of an uncontrolled burst of ENERGY. It’s actually not all that useful as a power source, because all that energy is released all at once.

❖ In order for electricity to be useful, we need a steady flow of it – a CURRENT. An electric current doesn’t just happen on its own. It needs a PATH to follow. And that’s what a CIRCUITis – a path that a current can flow along. You need more than just a wire.

❖ The most basic circuit is made of a few different components. First, there’s a POWER source, like an outlet in the wall, or a battery. The power source provides a steady supply of ELECTRONS. In the battery, the electrons come from the NEGATIVE terminal. From a wall outlet, electrons come from the SHORTER of the two slots, the HOT slot. The electrons need a path made of a good CONDUCTOR which is any material that allows electrons to move through it easily. Most METALS make good conductors, so we use metal wires as a path in electric circuits. The wires are surrounded by rubber or plastic because those materials are good INSULATORS. Insulators are the OPPOSITE of conductors – they’re materials that electrons have a hard time flowing through. Insulated wires keep electrons on course, and they protect us from the dangerous flow of electricity going through their metal cores.

❖ Along the circuit’s path, there’s usually a LOAD - a device that uses electricity. Electrons flow through the device, giving it POWER. When they flow out of the device, they head toward the OPPOSITE side of the power source. In a battery, that’s the POSITIVE terminal. In a wall outlet, that’s the TALLER of the two slots, the NEUTRAL slot.

❖ That’s the real key to an electric circuit – the ELECTRONS have to have SOME PLACE TO GO.

❖ Without a somewhere to flow into, the electrons will STOP MOVING and you’ll no longer have a CURRENT.

❖ If you look closely at an electric cord, you’ll see that it’s actually TWO separate insulated wires. Electrons flow out of the HOT slot, down one of the WIRES, into the LOAD through the wire on the other half of the cable, and back into the NEUTRAL slot. To control whether an electric device is on or off, you need a SWITCH. A switch controls the FLOW of electrons by opening and closing a circuit. When a switch is in the “OFF” position, the circuit is OPEN. When it’s in the “ON” position, the circuit is CLOSED, and electrons can flow.

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