Thermal energy/ heat in a parallel connection

AI Thread Summary
In a parallel connection, heat is produced based on the resistance values, with the current through R1 being double that through R2. The relationship of power (W1/W2) is determined to be 2:1, as power is proportional to current in parallel circuits. The formulas for calculating power include W = VI and W = I²R, with voltage being the same across both resistors. In contrast, if the resistors were in series, the power ratio would also be 1:2. Understanding these principles is crucial for analyzing thermal energy in electrical circuits.
AnneX
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Homework Statement
Nope, I am studying for a quiz
Relevant Equations
Not sure, but R and W could be directly proportional...
In a parallel connection heat is produced.

R1 = 5 Ohm

R2 = 10 Ohm

What is the relation of W1/W2?
1:4

1:2

2:1

1:8

3:1

I’d tend to say 1:2, but I am not really sure…
 
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Whats the formula for W? (When you know R and you know something else because they are in parallel.)
 
The current flowing through R1 is double the current flowing through R2
 
Do you know any formula for the heat generated W in a resistance R when a current I flows and there is a pd of V across it?
 
Or, actually, you've <nearly> solved it with your correct answer ##I_1 = 2 I_2##

Edited in <>
 
Do you know
Power=Voltage x Current ##W=VI##
Voltage = Current x Resistance ##V=IR##
So ## W= VI \ = \ IR I \ = \ I^2R##
or ## I = \frac{V}{R} ##
So ## W= VI \ = \ V \frac{V}{R} \ = \ \frac{V^2}{R} ##
 
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So, it is 2:1?
 
Yes.
You can always put some numbers in, as you do here, but the formulae are useful to remember.

Important thing here is, to know that the voltage is the same across both, when they in parallel.
So P=IV tells you that power is proportional to current. Current 2:1 so power 2:1

If they were in series, the current would be the same. If you work out the voltages,
P=IV tells you the power is proportional to the voltage for the same current.
 
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Thanks for the help 👍
One more question though, if the two resistors were in series would it be W1 : W2 = 1:2
 
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AnneX said:
One more question though, if the two resistors were in series would it be W1 : W2 = 1:2
Yes.
 
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