1. The problem statement, all variables and given/known data In the electric circuit shown in the figure, when the value of the variable resistor R3 is 25Ω, the current which flows into the power supply is 2A. Moreover, when the value of the variable resistor R3 is 5Ω a current of 1A flows into the resistance R2. Q1.Find the value of parallel combined resistance of resistance R1 and R2, Q2.Find the value of R2, Q3.When the resistance R3 is 25Ω how much electric power is consumed by resistance R1 2. Relevant equations V=IR R parallel combined =( R1 x R2) / (R1 + R2) 3. The attempt at a solution from the first given information i know that the volt at R3 is 50 then the volt at combined resistance is 30 then I tried various equations but then I stuck ,please help me this is the first time I met a physics problem with variable resistor, what is it really?