Question

What is Determine Thermo-EMF?

Answer

Determine Thermo-EMF - (a) The potential difference across R must be equal to the emf of standard cell, i.e. IR = E₀ ∴ I = E₀/R, (b) The small thermo-emf produced in the thermocouple e = xl (c) x = Iρ = IR/L = IRl/L' (d) The value of thermocouple for ordinary temperature difference is very low (10^-6 V). For this, the potential gradient x must be also very low (10^-4 V/m). Hence, a high resistance (R) is connected in series with the potentiometer wire in order to reduce current,