Heat and Thermal ExpansionHard
Question
The thermo emf of a thermocouple varies with the temperature θ of the hot junction as E = a θ + bθ2 in volts where the ratio a/b is 700oC. If the cold junction is kept at 0oC, then the neutral temperature is
Options
A.700oC
B.350oC
C.1400oC
D.no neutral temperature is possible for this thermocouple.
Solution
E = aθ + bθ2
At neutral temperature dE/dθ = 0
∴
= a + 2bθn = 0; θn = - 
Now
= 700oC(given)
θn = - 700/2 = - 350oC
Now θc = 0oC
So, θn > 0oC
But mathematically θn < 0oC
At neutral temperature dE/dθ = 0
∴
= a + 2bθn = 0; θn = - Now
= 700oC(given)θn = - 700/2 = - 350oC
Now θc = 0oC
So, θn > 0oC
But mathematically θn < 0oC
Create a free account to view solution
View Solution FreeMore Heat and Thermal Expansion Questions
A thermally insulated chamber of volume 2V0 is divided by a frictionless piston of area S into two equal parts A and B. ...A cup of tea cools from 80oC to 60oC in one minute.the ambient temperature is 30oC. In cooling from 60oC to 50oC. will t...A vessel is partitioned two equal halves by a fixed diathermy separator. Two different ideal gasses are filled in left (...The internal energy of as gas is given U = 5 + 2PV. It expands from V0 to 2V0 against a constant pressure P0. The heat a...Two absolute absolute scales X and Y assigned numerical values 200 and 450 to the triple point of water.What is the rela...