Big Idea: Moving a metal rod through a magnetic field can create a potential difference, aka voltage. It's a bit like magic but with physics!

Figure 4(a):

• Setting: A metal rod moving upward through a magnetic field.
• Magnetic Field: Direction is INTO the page (like an arrow shooting into the paper).
• Metal Rod: Zooming upwards like an elevator on energy drinks.

• The rod carries with it tiny particles called free electrons.
• Think of each moving electron like a mini-current (tiny river of charge) moving up the page.
• All these mini currents are moving parallel, like swimmers racing in their lanes!

• Because these electrons (treated like currents) are moving in a magnetic field, a force acts on them. (Ahem! Recall Topic D.2 for this).

• The direction of this force can be determined using something super cool: Fleming’s left-hand rule! 🤚

  How?

  • Picture a free electron moving up, now flip it! Imagine a positive charge moving down. That's right, they're opposites!
  • Using this flip-trick with the left-hand rule, we find the force on the electron pushes it to the right.

• As electrons drift to the right, the left end is left wanting – it's short on electrons!
• This creates a party of charges
  • End R (Right): Became the moody teenager room – negatively charged.
  • End L (Left): Became the sunshine room – positively charged.
• Outcome: A voltage (or potential difference) builds up between L & R. L is like the penthouse suite – higher potential.