step by step solution, values are given $($a$)$ Briefly describe the principle of operation and a typical application of a thermocouple temperature sensor$.[4]$ The following is an extract from a look$-$up table relating the emf produced by a type K thermocouple to the temperature of the hot junction. The cold junction is maintained at $0^$C$.($i$)$ Obtain the temperature corresponding to an emf of $1\mathrm{.}432$ mV$,$ to the nearest $0\mathrm{.}1^$C; $[2]($ii$)$ Obtain the emf produced at a temperature of $72\mathrm{.}4^$C; $[2]($iii$)$ In hand$-$held instruments, it is inconvenient to maintain the cold junction at a fixed temperature. Explain how this problem is overcome. $[2]($iv$)$ State two specific advantages offered by a thermocouple over other temperature sensors$.[2]$