I need help solving the electric DC circuit. Given inputs are:

R2=R3=R4=R5=300 Ohm

I need to calculate current I1 just in the second case.

First case:

I2=100mA,I3=40mA

E1=30V, E2=E3=30V

Because R1 and R6 are not given, in first case I tried with compensation theorem which gives 4 equations but I cant solve it because of R1 and R6. Which method other than compensation should I use if possible? Are resistors R1 and R6 even neccesary?

Second case:

E1=0V,E2=15V,E3=60V

So if I find R1 and R6 all parameters are known and it is easy to find I1.

Thanks for answers.

using mesh equations , i am able to solve this circuit easily. distribute the current throught the network by using curent variables. there will two unknown currents namely I1 and I2 only. and two resistor values are unknown. on total there will be four unknowns and there is chance of getting four independent linear equations from the circuit as there are four independent loops. Each equations does not contain all four unknowns so you can easily solve them. i got the solution easily. and later using those resistor values and the same approach determine the required current. if you want full soultion, i can provide you, send me an email to my gmail account vinodh2308.

thanks

vinodh kumar basavani