Question

The temperatures of the junctions of a bismuth-silver thermocouple are maintained at 0°C and 0.001°C. Find the thermo-emf (Seebeck emf) developed. For bismuth-silver, a = − 46 × 10⁻⁶ V°C⁻¹ and b = −0.48 × 10⁻⁶ V°C⁻².

Answer 1

Given:-

Difference in temperature, θ = 0.001°C,

a = − 46 × 10⁻⁶ V °C⁻¹

b = − 0.48 × 10⁻⁵ V °C⁻²

Emf, E = aθ + \[\frac{1}{2}\]bθ²

⇒ E = (− 46 × 10⁻⁶) × (0.001)

\[- \frac{1}{2}\times\left(0.48\times10^{-6}\right)\times \left(0.001\right)^2\]

= − 46 × 10⁻⁹ − 0.24 × 10⁻¹²

= − 46.0024 × 10⁻⁹

= − 4.6 × 10⁻⁸ V