Explanation: To determine the maximum voltage, we use the power formula relating power (P), voltage (V), and resistance (R): P = V²/R. We are given: * Power (P) = 20 watts * Resistance (R) = 2000 ohms To find the voltage (V), we rearrange the formula: V² = P * R V = √(P * R) Substitute the given values: V = √(20 watts * 2000 ohms) V = √(40000) V = 200 volts Therefore, the maximum DC or RMS voltage that can be connected across the resistor without exceeding its power rating is 200 volts. Connecting a higher voltage would dissipate more than 20 watts, potentially damaging the resistor. Lower voltages would dissipate less power, which is safe but not the maximum.