Edexcel IGCSE Physics · Spec 2.1-2.6
Charge & Ohm's Law: Using the Equations
Worked examples using the charge and Ohm's law equations.
Physics revision video
Charge & Ohm's Law: Using the Equations
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Spec 2.1-2.6
What you need to know
- Use Q equals I t for charge
- Use V equals I R, Ohm's law
- Rearrange both equations
Active recall
Quick check
Answer each question before opening the answer.
A current of 2 A flows for 30 s. How much charge passes?
Q = I × t = 2 × 30 = 60 C.
A 12 V supply drives 3 A through a resistor. What is its resistance?
R = V ÷ I = 12 ÷ 3 = 4 Ω.
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