Question

What is : (a) the highest (b) the lowest total resistances that can be obtained by combinations of four coils of resistances `4 Omega,8 Omega,12 Omega,24 Omega` ?

Answer 1

There are four of resistances `4 Omega, 8 Omega, 12 Omega "and " 24 Omega` respectively.
(a) If these coils are connected in series, then the equivalent resistance will be the highest, given by sum `4 + 8 + 12 + 24 = Omega`respectively.
(a) If these coils are connected in series. then equivalent resistance will be the highest, given by the sum `4 + 8 + 12 + 24 = 48 Omega`
(b) If these coils are connected in parallel, then the equivalent resistance will be the lowest, given by
`1/(1/4+1/8+1/12+1/24)=1/((6+3+2+1)/(24))=24/12=2 Omega`
Therefore, ` 2 Omega` is the lowest total resistance.