Electric Force, Field and Energy Notes

Electric Forces

• Pushes or pulls between charged objects.

• Like charges repel, unlike charges attract.

• Non-contact force.

Electric Fields

• Region around a charged object where other charges experience a force.

• E = F/q (E = electric field strength, F = force, q = test charge).

• Field lines show direction and strength.

  • Lines point away from positive charges and toward negative.

  • Lines point toward negative charges.

  • Closer lines = stronger field.

Creating Electric Fields

• Static charges.

• Moving charges.

• Changing magnetic fields.

• Measured in Newtons per Coulomb (N/C).

• Formula: E = F/q

Electric Current

• Charges created by transferring electrons.

  • Friction: Rubbing materials together transfers electrons.

    • Example: Balloon on hair.

  • Conduction: Charged object touches a neutral one.

    • Example: Touching a doorknob.

  • Induction: Charged object near a neutral object rearranges electrons.

    • Temporary charge.

    • Grounding creates permanent charge.

Series Circuits

• One path.

• Current is the same throughout.

• Voltage is shared.

• One failure stops the whole circuit.

Parallel Circuits

• Multiple paths.

• Same voltage across all branches.

• Current divides.

• One failure doesn't stop others.

Circuit Component

• Power Source (Battery):

  • Provides electrical energy.

• Conductors (Wires):

  • Connect components, allow current flow.

• Switch:

  • Controls electricity flow.

• Resistor (Light Bulb):

  • Uses energy to perform work (light).