Asked by  | 11th May, 2011, 12:58: AM

Expert Answer:

We know that when the resistance are connected in series and by question we get
When connected in parallel, by question  we get
From equation 1 and 2 we get two values of  and that is
let us take
Then from equation 1 we get
R+r=90, R=90-r, putting this value in equation 2 we get
when r is 60 ohms then R is 30 ohms and when r is 30 ohms then R is 60 ohms.

Answered by  | 11th May, 2011, 06:41: PM

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