What is the maximum power of the variable resistor R?

headshrinker
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Homework Statement



(a) For the circuit below, the value of R is adjusted so that each of the two 10Ω resistors dissipates 10W. Calculate the value of the variable resistor R.

(b) What is the value of R if it is adjusted to dissipate the maximum power possible? For this value of R, determine the current through the resistor R and through each of the parallel 10Ω resistors.

Homework Equations





The Attempt at a Solution



I've done part (a) and found the value of R to be 2.5ohms. i have no idea how to do part (b). can anyone help?!

Thank you!
 

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If you know what R is, what is the power dissipated in this resistor? (as a function of R)
do you know any method for finding the maximum value of a function?
 
i have no idea! I am new to this stuff! do u know?

thanks!
 
anyone?
 

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