Question

the effective resistance in series combination two equal resistance is s when they are joined parllel the total resistance is p if s=np then the minimum possible value of n is

Answer 1

Answer:n=4

Explanation:

=R1+R2andP=R1R2/R1+R2  

S=nP⇒R1+R2=n(R1R2)/R1+R2

⇒(R1+R2)^2=nR1R2⇒n=R11+R22+R1R2/R1R2

n=R1/R2+R2/R1+2

Arithmetic mean gt Geometric mean

Minimum value of n is 4 .

Answer 2

Explanation:

in series

r+r=s so s=2r equation 1

now in parellel

r/2=p equation 2

now equation  1/2 gives us s/p=4

substituting s=np

n=4 which is minimum possible value of n