[Leejohnston]

## Ohm’s Law — How Electricity Actually Flows

### 1. The Equation

V = I × R

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### 2. What Each Symbol Means

- V = voltage (volts)
- I = current (amps)
- R = resistance (ohms)

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### 3. What the Equation Is Telling Us

Ohm’s Law describes how easily electric current flows through a circuit.

- Higher voltage → more push
- Higher resistance → more opposition
- Current is the result of both

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### 4. Where It Comes From (Intuition)

Think of electricity like water in a pipe:
- Voltage = pressure
- Current = flow rate
- Resistance = pipe narrowness

More pressure or a wider pipe → more flow.

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### 5. Worked Example

If:
- Voltage = 12 V
- Resistance = 6 Ω

Current = V ÷ R
= 12 ÷ 6
= **2 amps**

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### 6. Real-World Applications

- Electronics design
- Fuse ratings
- Power supplies
- Battery safety

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### 7. Common Mistakes

- Forgetting units
- Mixing AC and DC concepts
- Assuming resistance never changes

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### Try It Yourself

What happens to the current if:
- resistance doubles?
- voltage is halved?