Given the circuit (a). Simplify the circuit, that the effective circuit (b) behaves exactly like (a) for any observer measuring between clamps A and B. That means: Calculate Ri and Uq. R R3 RA R -O A OB -O A Olua [Ri OB (a) (b) Values: U=120V, R=400, R2=50 Q, R3=60 Q and R4= 300.