Current Electricity Charging Discharging Of Capacitors Question 128
Question: The thermo e.m.f. of a thermocouple varies with the temperature $ \theta $ of the hot junction as $ E=a\theta +b{{\theta }^{2}} $ in volts where the ratio a/b is $ 700^{o}C. $ If the cold junction is kept at $ 0^{o}C, $ then the neutral temperature is
[AIEEE 2004]
Options:
A) $ 700^{o}C $
B) $ 350^{o}C $
C) $ 1400^{o}C $
D) No neutral temperature is possible for this thermocouple
Show Answer
Answer:
Correct Answer: D
Solution:
Comparing with standard equation $ E=\alpha t+\frac{1}{2}\beta t^{2} $ a = \alpha \text{ and } b = 2\beta
Therefore $ t _{n}=-\frac{a}{2b}=-\frac{1}{2}\times 700=-350^{o}C $ This is not possible.
BETA
