Draw a circuit with a battery of 90 V is connected to four
resistors, R1 =10 Ω, R2,= 20 Ω , R3 =30 Ω and
R4= 40 Ω, as follows. Resistors R1 and
R2 are connected in parallel with each other, resistors
R3 and R4 are connected in parallel with each
other, and both parallel sets of resistors are connected in series
with each other across the battery. (20 Points)
a. Find the equivalent resistor R12, for the partial
circuits...