Explanation: Voltage regulation in a power supply describes how much the output voltage changes from no load to full load. It's calculated as the percentage difference between the no-load voltage and the full-load voltage, relative to the full-load voltage. The formula for voltage regulation is: Regulation (%) = [(V_no_load - V_full_load) / V_full_load] * 100 Given: V_full_load = 200 V Regulation = 25% We can rearrange the formula to solve for V_no_load: 0.25 = (V_no_load - 200) / 200 0.25 * 200 = V_no_load - 200 50 = V_no_load - 200 V_no_load = 50 + 200 V_no_load = 250 volts This calculation shows that with 25% regulation, the voltage increases by 25% of the full-load value when the load is removed. Thus, 25% of 200 V is 50 V, which added to 200 V gives 250 V. The other options are incorrect based on this definition.