Question

two resistances when connected in parallel give resultant value of 2 Ohm and when connected in series the value becomes 9 Ohm calculate the value of each resistance???????

answer...pls

Answer 1

★ Hey mate ★


here is your correct answer !!


let the resistance be R1

let the second resistance be ==> R2


now , according to question !!


R1 + R2 = 9 Ω ----------------(1)


when , they are connected is parrallel


1 /R1 + 1 / R2= R1 + R2 / R1 × R2


R1 × R2= 2 Ω × 9


{ from equation 1 }



R1 × R2= 18 Ω


also ,


we have ,


( R1 - R2 )² = ( R1 + R2 ) ² - 4× R1 × R2


(R1 - R2 ) ² = 9 ² - 4 × 18



( R1 - R2 ) ² = 81 - 72



R1 - R2 =√ 9



R1 - R2 = ± 3----------------(2)




now , from equation



R1 + R2 = 9
R1 - R2 = 3
==========
2R1 = 12


R1 = 6 Ω


R2 = 3 Ω




hence , value of each resistance is

★ R1 = 6 Ω , R2= 3 Ω ★


hope it helps you dear !!!



$thanks$