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]

• A.            \[{{700}^{o}}C\]
• B.            \[{{350}^{o}}C\]
• C.            \[{{1400}^{o}}C\]
• D.            No neutral temperature is possible for this thermocouple