(Solved): In the following electrical circuit, the resistors R1 have a resistance of 20.R2 exhibits a ...

In the following electrical circuit, the resistors $R_1$ have a resistance of $20?.R_2$ exhibits a resistance of $80?.l_2$ was measured as $1\mathrm{A}$. b) Please derive the source voltage $U$. c) Please calculate the total power that is consumed by the electrical circuit. d) For the two cases $R_2?0$ or $R_2??$, please calculate the total power consumption.