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Electricity · Chapter 2: Electromagnets

Year 11 Science · About 17 minutes with activities · Turn your sound on

Chapter 2 · Electromagnets
Lets go on commandno claw, no hook
Thumb: current
Fingers: fieldanticlockwise from above
Thumb points to Nfingers follow the current
Wire → coil → corebar heights are illustrative
Electrical methodno current, no magnet
Switch it on and offthat is the big advantage

Chapter 2 recap

  • Right-hand grip rule: thumb = current, fingers curl with the field (× clockwise, • anticlockwise). Solenoid rule: fingers curl with the current, thumb points to N.
  • B = KI/d, K = 2 × 10⁻⁷. More current or a smaller distance → stronger B. Solenoid: more current, more coils, a soft iron core.
  • Magnets: stroking or a current lines up the domains; hammering, heating or dropping disrupts them. Electromagnets switch on and off: scrapyard cranes, eye splinters.
  • Next: Chapter 3 · Generators and AC

How does a scrapyard crane drop a car on command?

Chapter 2 · About 17 minutes · sound on

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