Final answer:
The total resistance of a parallel DC circuit with resistances of 12 ohms and 30 ohms is 8.57 ohms.
Step-by-step explanation:
In a parallel DC circuit, the total resistance depends on the individual resistances of the branches. To find the total resistance, we can use the formula:
Rtotal = 1 / (1/R1 + 1/R2)
where R1 and R2 are the resistances of the two branches. Plugging in the values, we get:
Rtotal = 1 / (1/12 + 1/30)
Calculating this gives us a total resistance of 8.57 ohms.