Question

The smallest temperature difference that can be measured with a combination of a thermocouple of thermo e.m.f. 30 $\mu V$per degree and a galvanometer of 50 ohm resistance capable of measuring a minimum current of 3 × 10^–7 ampere is

• A. 0.5 degree
• B. 1.0 degree
• C. 1.5 degree
• D. 2.0 degree

Answer 1

Answer: (A)

0.5 degree

Answer 2

By using E = aθ ⇒ i R = aθ

⇒ 3 × 10^–7 × 50 = 30 × 10^–6 × θ ⇒ θ = 0.5 degree