For the silver–lead pair, the constants a and b are given as 2.50 V ^ C ⁻¹ and 0.012 V ^ C ⁻² , respectively. If a silver–lead thermocouple has its colder junction kept at 0^ C ,

Step-by-step solution

The thermo-emf E of a thermocouple with the cold junction at 0^ C and the hot junction at t^ C is given by the relation: E = at + 1 2 bt^2 The neutral temperature t_n is the temperature of the hot junction at which the thermo-emf is maximum, which means dE dt = 0 . dE dt = a + bt_n = 0 t_n = - a b Given a = 2.50 V ^ C ⁻¹ and b = 0.012 V ^ C ⁻² : t_n = - 2.50 0.012 = -208.3^ C Since the colder junction is kept at 0^ C , the hot junction must be at a temperature t > 0^ C . Because t_n The inversion temperature t_i is