Physics - Thermodynamics - Laws of thermodynamics - Impossible Machines

Present 6 hypothetical machines and ask 'Could this work? Yes or No.' (1) 'A car that runs forever without fuel' (No - violates 1st law, can't create energy from nothing). (2) 'A power plant that converts 100% of heat into electricity' (No - violates 2nd law, always some waste heat). (3) 'A fridge t