Electric Physics

Electric Physics Ex...brrr...plained.

⚛ Protons & Electrons

• Protons → Positive (+)

• Electrons → Negative (-)

• Electrons move more easily than protons

⚖ Neutral Atoms vs. Ions

• Neutral Atom: Electrons = Protons

• Ion: Electrons ≠ Protons

  • Anion (-): Extra electrons

  • Cation (+): Fewer electrons

🔋 Elementary Charge & Coulomb

• Elementary charge (e) is defined as the charge of one electron (-e) or one proton (+e):

• 𝑒 = 1.6 × 10⁻¹⁹ C

• Where C = Coulomb

• 1 C = 6.24 × 10¹⁸ protons

⚡ Conductors vs. Insulators

• Metals (Conductors): Free-moving electrons through the lattice of positive ions.

• Non-metals (Insulators): Tightly bound electrons

⚡ What is Current?

• Flow of electric charge

• Carried by electrons (in wires) or ions (in solution)

• Requires a complete circuit

• All circuits require an energy source, wires, and a circuit element.

🔄 Conventional vs. Electron Flow

• Conventional Current (I, current): + to -

• Electron Flow (electron current): - to +

Representing electric circuits

📏 Current Formula

• 𝑰 = 𝑸/𝒕 (Charge per second), I = Current (A), Q = amount of charge and t = time (s)

• 𝑸 = 𝒏ₑ × 𝒒ₑ (Charge = No. of electrons × charge per electron)

• Unit: Amperes (A), 1A = 1 Coulomb/s

📊 Measuring Current - Ammeter v.s. Voltmeter

• Ammeter measures current

• Connected in series with the circuit.

• A voltmeter measures voltage

• Connecting in parallel across components.

💧 Water Analogy for Current

• Battery = Water pump

• Current = Water flow

• Light bulb = Turbine (converting energy)

• Charges are not used up, like chain links in a bicycle

🔋 Energy for Electrons

• Electrons need energy to move, provided by the battery.

• When a circuit connects two ends of the battery, the battery transforms chemical energy into electrical potential energy.

⚡ Potential Energy in a Circuit - Potential Difference

• Potential energy is stored as a separation of charge between battery terminals.

• This is called potential difference (V), measured in volts (V).

💡 Voltage Drop

• Voltage drop is the energy lost by each coulomb of charge.

• Equation: 𝑉 = 𝐸 / 𝑄

  • 𝑉 = potential difference (V)

  • 𝐸 = electric potential energy (J)

  • 𝑄 = charge (C)

⚙ Energy in a Circuit

Energy (E) = 𝑉 × 𝐼 × 𝑡

• 𝐸 = energy (J)

• 𝑉 = potential difference (V)

• 𝐼 = current (A)

• 𝑡 = time (s)

🧮 Power Formula

Power (P) is energy used per second: 𝑃 = 𝐸 / 𝑡

• 𝑃 = power (W)

• 𝐸 = energy (J)

• 𝑡 = time (s)

Power equation: 𝑃 = 𝑉 × 𝐼

• 𝑉 = potential difference (V)

• 𝐼 = current (A)

• Voltage and current are easily measured in a circuit.