About the NPN Circuit Pt 1
The collector is attached to the upper bus. the middle prong or the base is connected to the resistor. The emitter is connected to the positive side of the buzzer. So when the middle prong gets given electricity it tells the emitter to emit electricity. Which will turn the buzzer on when the tentacles are connected.
Capacitors In A Circuit - Small Capacitor
The small compasitor is the same as the larger one, except that it stores les energy, and makes the LED dim much quicker
How does the reed switch work
When there is no magnetic field, the switch stays open so no electric current can get through.
When there is a magnetic field nearby, the metal 'reeds' inside the switch attract. They touch each other, so the switch is now closed, allowing current flow.
How Buzzer Circuit Works
When you touch the wires together the alarm sounds because the circuit has been closed.
About the NPN Circuit Pt 2
The tentacles connect the red power wire to the base pin of the transistor, which turns on the emitter.
About the PNP Transistor
the npn is off unless you connect power to the base, and the pnp is on unless you connect power to the base.