12) [2 marks each] Short answer questions #4 a) Consider the material for the side walls of a swimming pool. Name and define its thermal material property that can be optimized to slow down heat loss from the water in the pool through the side walls. b) Explain the mode of operation of a piezoelectric transducer used to detect faults inside solid materials. c) Explain the charge carrier population with which current is conducted inside an intrinsic semiconductor and tell how it is different from the charge carrier population with which current is conducted inside a doped semiconductor