Electricity – Physics – Visions Classes

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⚡ Electric Current & Voltage

Electricity is the flow of electric charge (electrons) through a conductor.

I = Q/t 1 Ampere = 1 Coulomb per second

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Watch electrons (dots) flow from the negative terminal of the battery through the resistor to the positive terminal!

Current flows from + to − (conventional) | Electrons flow from − to + (actual)

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At constant temperature, current through a conductor is directly proportional to the voltage across it.

          🌟 Ohm's Law
          V = I × R
        

V

I

R

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All components in a single loop. Same current flows through all resistors.

R_total = R₁ + R₂ + R₃

Current same: I₁ = I₂ = I₃

Multiple paths for current. Same voltage across all resistors.

1/R = 1/R₁ + 1/R₂ + 1/R₃

Voltage same: V₁ = V₂ = V₃

Power: P = V × I = I²R = V²/R (unit: Watt W)

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Q: A 6V battery is connected to a 30Ω resistor. Find current and power dissipated.

1

V = 6V, R = 30Ω

2

I = V/R = 6/30 = 0.2 A

3

P = V×I = 6×0.2 = 1.2 W

4

P = (0.2)² × 30 = 0.04 × 30 = 1.2 W ✓

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Electricity mastered! 🎉