Question

when two resistors are connected in series with a cell of EMF 5 volt and negligible internal resistance a current of 2 ampere flows in the circuit. when the resistors are connected in parallel the main current is 25/3 A. Calculate the value of each resistance.​

Answer 1

Answer:

R1= 11/8

R2 = 9/8

Explanation:

Rs = R1 + R2

I = E/Rs+r

2 = 5/ Rs+0

Rs = 2/5= R1 + R2........ (1)

Rp=R1.R2/R1 + R2

I = E/ Rp+ r

I=25/3

Rp=2R1.R2/5

(R1 + R2= 5/2)

R1. R2= 3/2

using relation

(R1 - R2) ^2= (R1+R2) ^2 - 4R1.R2

R1 -R2= 1/4.......(2)

using 1 and 2 ( adding)

R1 =11/8

R2 =9/8.