Circuit Breaker Challenge: Ohm's Law
Grade 9 Physics East Baton Rouge Tara High School Hands-On Problem Solving
Learning Objectives - I Can...
I can identify the three variables in Ohm's Law (V, I, R) I can choose the correct formula based on what I need to find I can solve electrical problems step-by-step I can include proper units in my calculations I can apply Ohm's Law to real-world devices
Success Criteria
✓ Identify known and unknown values in each problem ✓ Show all work with proper mathematical steps ✓ Use correct units (volts, amps, ohms) ✓ Check answers for reasonableness ✓ Explain the relationship between V, I, and R
Quick Check: Formula Practice
Work with your partner: If you need to find CURRENT, which formula? If you need to find VOLTAGE, which formula? If you need to find RESISTANCE, which formula? 30 seconds per question!
Problem-Solving Steps
1. READ the problem carefully 2. IDENTIFY what you know (given values) 3. IDENTIFY what you need to find 4. CHOOSE the correct formula 5. SUBSTITUTE values and solve 6. CHECK your answer and units
Engineer's Mindset
"Every electrical problem is a puzzle waiting to be solved. The key is breaking it down step by step." - Electrical Engineering Principle
Challenge 1: Phone Charger
📱 SCENARIO: Phone charger provides 12 volts to a device with 6 ohms resistance 🎯 FIND: How much current flows through the charger? ⚡ Work in pairs - 3 minutes Show all steps on your whiteboard!
Challenge 1: Solution
Given: V = 12V, R = 6Ω Find: I = ? Formula: I = V/R Solution: I = 12V ÷ 6Ω = 2A Answer: 2 amperes of current flow through the charger
Challenge 2: Space Heater Mystery
🔥 SCENARIO: Space heater plugged into 120V outlet draws 10 amps 🎯 FIND: What is the resistance of the heater? ⚡ Individual work - 4 minutes Remember: Include units in your final answer!
Challenge 2: Solution
Given: V = 120V, I = 10A Find: R = ? Formula: R = V/I Solution: R = 120V ÷ 10A = 12Ω Answer: The heater has a resistance of 12 ohms
Challenge 3: Flashlight Fix
🔦 SCENARIO: Flashlight bulb has 4 ohms resistance, 3 amps current flowing 🎯 FIND: What voltage is supplied to the bulb? ⚡ Partner work - 3 minutes Bonus: Why might this information help fix a broken flashlight?
Challenge 3: Solution
Given: R = 4Ω, I = 3A Find: V = ? Formula: V = I × R Solution: V = 3A × 4Ω = 12V Answer: 12 volts is supplied to the bulb
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