P. 4429. It is not suggested to turn off the projectors used nowadays. After the lamp was switched off the cooling fan is working for some minutes and only then the projector is allowed to unplug. Edith states that this is unnecessary, ``If the lamp is not on, it cannot be warmer, and the lamp endures at working temperature. So if we do not want to use the projector, it can be unplugged.'' Is Edith right?
Solution (in Hungarian)