Q. 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 $3 \times 10^{- 7}amp$ is
A) 0.5 degree
B) 1.0 degree
C) 1.5 degree
D) 2.0 degree
Explanation
(a) $i = \frac{e}{R} \Rightarrow 3 \times 10^{- 7} = \frac{(30 \times 10^{- 6}) \times \theta}{50} \Rightarrow \theta = 0.5{^\circ}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.