Final answer:
The magnitude of the potential difference across the 20-ω resistor can be calculated using Ohm's Law.
Step-by-step explanation:
The magnitude of the potential difference across the 20-ω resistor can be determined using Ohm's Law, which states that V = IR, where V is the potential difference, I is the current, and R is the resistance.
In this case, if we know the current passing through the 20-ω resistor, we can calculate the potential difference. If the current passing through the resistor is given as I, then the potential difference across the resistor is V = I * 20-ω.
For example, if the current passing through the resistor is 2 Amperes, then the potential difference will be V = 2 A * 20-ω = 40 Volts.