Current Electricity Ques 56
56. A thermocouple of negligible resistance produces an e.m.f. of $40 \mu V /{ }^{\circ} C$ in the linear range of temperature. A galvanometer of resistance 10 ohm whose sensitivity is $1 \mu A /$ div, is employed with the termocouple. The smallest value of temperature difference that can be detected by the system will be
(a) $0.5^{\circ} C$
(b) $1^{\circ} C$
(c) $0.1^{\circ} C$
(d) $0.25^{\circ} C$
[2011M]
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Answer:
Correct Answer: 56.(d)
Solution:
- (d) 1 division $=1 \mu A$
Current for $1^{\circ} C=\frac{40 \mu V}{10}=4 \mu A$
$1 \mu A=\frac{1}{4}{ }^{\circ} C=0.25^{\circ} C$.
BETA
