If the electricity supply was interrupted while you were baking and you had to leave home before it was restored, the oven will not automatically turn on when the electricity comes back. Electric ovens typically do not have a feature that resumes operation automatically after a power outage.
When the power supply is interrupted, the oven's settings and timers are reset. You would need to manually turn on the oven and set the desired temperature and cooking time again once the electricity is restored. It's important to follow the manufacturer's instructions and safety guidelines when operating the oven after a power outage.
If you're concerned about the food you were baking, it's advisable to check its condition before continuing the cooking process or consuming it, as the interruption in heat may have affected its cooking time or quality.