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Resistors In Series and Parallel Power Rating

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danner123

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If I put two resistors in series (load 1) that are both power rated at 50W, does that mean the power rating over the resistor load 1 becomes 100W (meaning I just add the the power ratings of the two resistors)?

If I put two resistors in parallel that are both power rated at 50W, what does the overall load 2 power rating become?

Thanks!
 

danner123 said:
If I put two resistors in series (load 1) that are both power rated at 50W, does that mean the power rating over the resistor load 1 becomes 100W (meaning I just add the the power ratings of the two resistors)?
Click to expand...
No because it could happen for one resistor to dissipate 70 W and for another to dissipate 10 W which is bad even though the equivalent power dissipation is 80 W and hence a resistor rated for 100 W would be suitable.
 
Resistor power rating doesn't change, it's intrisic property of a physical component. But if you use serial or parallel connection, you change power dissipation at every resistor due to various voltage/current. P = U * I - school formula.
In serial connection you have total P = (U1 + U2) * I, in parallel P = U * (I1 + I2). You can decrease power at every resistor this way, while keeping total power dissipation.
 
The power rating of resistors add either if they are connected in series or in parallel, for same resistance values.
Two 50 W are rated 100 W anyway you connect them if their resistance is the same.
 
I did some calculation. I left the parallel resistors case to be developed by you.


 

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