A

Step 1: Calculate the applied voltage (V_a)
In an AC circuit with a resistor (R) and an inductor (L), the applied voltage can be found using the formula:
$$ V_a = \\sqrt{V_R^2 + V_L^2} $$
Given, V_R = 120 V and V_L = 160 V:
$$ V_a = \\sqrt{(120)^2 + (160)^2} $$
$$ V_a = \\sqrt{14400 + 25600} $$
$$ V_a = \\sqrt{40000} $$
$$ V_a = 200 ext{ volts} $$
Step 2: Calculate total impedance (Z)
The total impedance can be calculated using Ohm's law:
$$ Z = \\frac{V_a}{I} $$
Where I = 1.0 A. Therefore,
$$ Z = \\frac{200}{1.0} $$
$$ Z = 200 ext{ ohms} $$
Step 3: Calculate the potential difference in case of direct current
In a direct current circuit, the total voltage is equal to the sum of the voltage across the resistor and the inductive reactance. However, inductance does not influence direct current since it only has a resistive component:
Therefore, the potential difference V_dc in a DC circuit will equal the voltage across the resistor:
$$ V_{dc} = V_R = 120 ext{ volts} $$
Final Answer: The virtual value of the applied voltage is 200 volts, the total impedance is 200 ohms, and the potential difference in a DC circuit is 120 volts.