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Heating and Chemical Effect of Current — JEE physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceJEE physicsHeating and Chemical Effect of Current1 Mark
MCQ
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 $3 \times 10 amp$ is
  • ✓
    0.5 degree
  • B
    1.0 degree
  • C
    1.5 degree
  • D
    2.0 degree
✓

Answer

Correct option: A.
0.5 degree
(a) $i=\frac{e}{R} \Rightarrow 3 \times 10^{-7}=\frac{\left(30 \times 10^{-6}\right) \times \theta}{50} \Rightarrow \theta=0.5^{\circ}$

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