Comments by "The Great Zoom" (@thegreatzoom5073) on "Electrical Current Explained - AC DC, fuses, circuit breakers, multimeter, GFCI, ampere" video.

  1. The speed of electrons won't really change based on load, that depends on the properties of the material they're moving through. Changing the load in a circuit is just changing how much the components in that circuit resist the flow of current. More appliances means more loads in parallel, and loads in parallel will draw current independently of one another. Another way to look at it is power. If you run an oven and a TV, they both require power to function correctly. Power is a function of current and voltage, so it follows that with more power from more appliances you'd be drawing more current.
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  2. It's not just the fact that they store energy, but that they do so over time. This gives some interesting properties, like capacitors/inductors having "resistance" (in the form of impedance) when the voltage they see changes rapidly. Explaining this wouldn't really help with understanding what these parts are used for though. One way inductors are used is as a choke, or a component that limits current spikes. Inductors store energy in a magnetic field and the more current that flows through the inductor in a short amount of time, the stronger the magnetic field becomes. This magnetic field will actually interact with the current in the inductor and try to prevent it from changing too quickly. The faster the current wants to change, the stronger the magnetic field that opposes it. This forces the current to change slowly rather than in an instant and can be useful in some devices that may see intermittent shorts where current suddenly shoots up.
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  3. The lamps in parallel have an equivalent resistance of 0.5 ohms. Using that you get 1.5/0.5 = 3 amps. The reason this happens is the voltage seen on the positive side of both bulbs is equal (1.5V) because the wire ideally has no voltage drop. We know that the voltage on the negative side has to be zero because it goes back to the battery, so we can say that both bulbs have a 1.5V drop across them. Knowing this and the resistance of each bulb, you find that the current through each individual bulb is 1.5/1 = 1.5A. Kirchhoff's Current Law states that the currents through a node must add up to zero, or that you cannot have current building up anywhere. So since the current leaving both bulbs is 1.5A and those two wires meet and go back to the battery, we can just add them up and get 3A.
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  4. Watts are a measurement of power, which is current times voltage. For example, you can describe the power dissipated by a resistor as the current moving through it times the voltage across it.
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