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QAIPM-2011-Ch-1834: NEET 2011 Physics - Class 12 AIPM-2011-Ch-1834 Solution: A thermocouple of negligible resistance produces an e.m.f. of…

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/\text{division}

, is employed with the thermocouple. The smallest value of temperature difference that can be detected by the system will be

Step-by-Step Verified Solution

For minimum deflection of 1 division required current = 1 �A _ Voltage required = IR = (1�A) (10) = 10 �V _ 40 �V _ 1�C _ 10 �V _ 1 4 �C = 0.25�C