1. **State the problem:** We are given a device with an electrical power consumption of 200W and a useful output power of 120W. We need to find the power losses in Watts. 2. **Formula used:** Power losses can be found by subtracting the useful output power from the total power consumption: $$\text{Power losses} = \text{Power input} - \text{Useful power output}$$ 3. **Apply the values:** $$\text{Power losses} = 200 - 120$$ 4. **Calculate:** $$\text{Power losses} = 80$$ 5. **Interpretation:** The power losses represent the energy lost, usually as heat or other forms, during the operation of the device. **Final answer:** The power losses are 80 Watts.