• The electric field powers up electrons.
• As electrons move, they bump with positive ions and transfer energy, but not because they speed up/slow down.
• Electric current in a series circuit remains consistent.
• Potential difference (or pd) indicates electrical potential energy transferred when an electron moves between two points in a circuit.
• Defined as V = \(\frac wq\)​ where:
  • V = potential difference
  • W = work done (energy transferred)
  • q = charge
• Unit: JC⁻¹ (joules per coulomb), named "volt" (V) in honor of Alessandro Volta.

🌎 Real-world example: Think of PD like the pressure difference in water pipes - the bigger the difference, the faster the flow!

• An electron gains energy in the cell and then moves around the circuit.
• Small pd in connectors, but bigger pd in devices like lamps where energy is intentionally transferred to make it glow.

🌎 Real-world example: Imagine a rollercoaster. The cell is like the lift hill, giving the coaster potential energy. The connectors are calm parts of the track. The lamp? That's the thrilling drop, using up energy!

• Early scientists thought electricity flowed like a fluid.
• Benjamin Franklin introduced the terms “positive” and “negative”.
• They mistakenly thought a positive charge flowed in wires, hence the "conventional current".
• But, electrons (negative) are the ones moving - "electron current".
• We keep both terms as flipping the established rules based on the new knowledge would be too confusing.

🌎 Real-world example: Imagine being taught your entire life that the sky is green. Then one day, you realize it's blue. But everyone still uses "green" to avoid confusion. That's like the two currents!