Figure shows a simple potentiometer circuit for measuring a small e.m.f. produced by a thermocouple. The meter wire PQ has a resistance 5 Ω Ω and the driver cell has an e.m.f. of 2 V. If a balance point is obtained 0.600 m along PQ when measuring an e.m.f. of 6.00 mV, what is the value of resistance R
Text Solution
Verified by ExpertsThe correct answer is:
A
The voltage per unit light of the meter wire PQ is
i.e. 
.
Hence potential difference across the meter wire PQ is 
.
The current drawn from the driver cell is
.
The resistance R is
.
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