Yes, that's correct. When you set your 1000-watt microwave to cook at 50% power, it means the microwave is operating at half its maximum power output. In this case, it will be using 500 watts to cook the food.
Microwave ovens with power settings allow you to adjust the cooking power level, typically ranging from 10% to 100%. When you choose 50% power, the microwave will cycle on and off during the cooking process to achieve the desired power level. This is how it reduces the energy consumption to half, using only 500 watts instead of the full 1000 watts. The lower power setting results in longer cooking times, but it can be useful for cooking or reheating certain foods more gently and evenly.