B. When two resistors are connectedin series, their effective resistan

1.	B. When two resistors are connectedin series, their effective resistanceis 80 Ω. When they are connectedin parallel, their effective resistanceis 20 Ω. What are the values of thetwo resistances?(Answer : 40 Ω , 40 (2)
Answer» let the resistance be R1 and R2 so, R1 + R2 = 80 and R1R2/(R1+R2) = 20 => R1R2 = 20*(80) = 1600 so, R1(80-R1) = 1600=> R1² -80R1+ 1600 = 0 => R1 = 40 and R2 = 40

B. When two resistors are connectedin series, their effective resistanceis 80 Ω. When they are connectedin parallel, their effective resistanceis 20 Ω. What are the values of thetwo resistances?(Answer : 40 Ω , 40 (2)

Answer»

let the resistance be R1 and R2

so, R1 + R2 = 80

and R1*R2/(R1+R2) = 20

=> R1*R2 = 20*(80) = 1600

so, R1(80-R1) = 1600=> R1² -80R1+ 1600 = 0

=> R1 = 40 and R2 = 40