Answer:
the amount of power went over the circuit breaker limit
Step-by-step explanation:
The circuit breaker cut off everything in the bathroom because the limit was 40 amperes but the amount of power being used in the bathroom exceeded the limit, going up to 46.25 amperes. A way to stop this may be using an extension cord to plug in the hair dryer somewhere outside the bathroom while still being able to use it in the room, or instead of using the light in the bathroom, try using a night light or just light from outside the room that can still provide enough light in the bathroom.