question_answer

Give reasons why is a platinum wire used in a resistance thermometer.

Answer:

                The reasons for using a platinum wire in a resistance thermometer are: (i) The resistance of a platinum wire increases uniformly with the rise in temperature (from \[\text{2}00{}^\circ \text{C}\] to\[\text{12}00{}^\circ \text{C}\]). (ii) It does not react chemically with other substances (iii) Its melting point is quite high (\[\text{18}00{}^\circ \text{C}\]).