Question

Try to explain why vacuum cleaners are forbidden to clean the damp dust or liquid waste? [160 words]

Answer 1

If you submerge an entire vacuum cleaner into water and turn it on, it will short out if you're lucky. If it doesn't, it will electrocute anyone who's in contact with the water.  

If you just stick the tube in water, a wet/dry vac will suck it up because it's designed for that. If it's an ordinary vacuum, either a) the force required to suck up the water will short a circuit or destroy the fan, or b) some water will get into the bag, clogging everything up and probably destroying the fan or, c) water droplets will get into the fan motor itself, frying out the wires and creating a fire or electrocution hazard.