4.5W heating wire Electrical Advice

4.5W heating wire Discussion Thread4.5W heating wire Electrical Advice

Hi, I am not an electrician. Not even good a physics. My question is basic maths. I want to check an answer I got from AI from someone fluent in terms.

So I asked AI, how long a 3mm 8AWG Heating Resistor Nichrome Wire for Heating Elements would have to be to raise temperature of 100ml water from 20°C to 40°C if connected to 2A mobile phone charger. Here is what it writes.

Let's recalculate with the correct logic:

1. Power needed: 4.65W (as calculated earlier)
2. Charger output: 5V, 2A (10W max)

For our heating element, we want to match the resistance to use 4.65W at 5V:

1. Using P = V²/R, we can calculate the required resistance:
   R = V²/P = 5²/4.65 ≈ 5.38Ω
2. For 3mm (approx. 8 AWG) Nichrome wire with 0.15 Ω/m resistance:
   Length = 5.38Ω / (0.15 Ω/m) ≈ 35.87 cm

Does the calculation have merit?

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