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

What is (a) the highest, (b) the lowest total resistance that can be s

1.	What is (a) the highest, (b) the lowest total resistance that can be secured by combinations of four coils of resistances 4 Omega, 8 Omega, 12 Omega, 24 Omega ?
Answer» SOLUTION :( a )The highest resistance can be secured (or obtained) by connecting all the four COILS in series. In this CASE, `R_s + R_1 + R_2 +R_3 +R_4` ` = 4 + 8 + 12 +24 =48 Omega` Thus, the highest resistance which can be secured is `48 Omega`. ( B )The lowest resistance can be secured by connecting all the four coils in parallel. In this case, `1/R_p = 1/R_1 + 1/R_2 + 1/R_3 + 1/R_4` `1/4+1/8 +1/12 + 1/24` `= (6 + 3 + 2 +1)/(24)` ` =12/24` `:. R_p = 24/12` `=2 Omega` Thus, the lowest resistance which can be secured is `2OMEGA`.