Explanation: This question involves Ohm's Law, a foundational principle in electronics and amateur radio. Ohm's Law describes the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit. To find the voltage across a resistor, the formula derived from Ohm's Law is V = I × R. Given: * Current (I) = 2 amperes * Resistance (R) = 50 ohms Applying the formula: V = 2 A × 50 Ω V = 100 volts Therefore, the voltage across the resistor is 100 volts. Understanding Ohm's Law is critical for anyone working with radio equipment, as it's essential for circuit design, troubleshooting, and power calculations. Options A, B, and C are incorrect as they do not follow the correct application of Ohm's Law.