Current Electricity and Electrical InstrumentHard
Question
The resistance of the series combination of two resistances is S. When they are joined in parallel through total resistance is P. If S = nP, then the minimum possible value of n is
Options
A.4
B.3
C.2
D.1
Solution
Let resistances be R1 and R2
So, S = R1 + R2;
P =
S = nP
R1 + R2 =
(R1 + R2)2 = nR1R2
If R1 = R2, so minimum value of n = 4.
So, S = R1 + R2;
P =

S = nP
R1 + R2 =

(R1 + R2)2 = nR1R2
If R1 = R2, so minimum value of n = 4.
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