InterviewSolution
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InterviewSolution
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One junction of a certain thermoelectric couple is at a fixed temperature r T and the other junction is at temperature T . The thermo electromotive force for this is expressed by `E=K(T-T_(r ))[T_(0)-(1)/(2)(T+T_(r ))]`. At temperature `T=(1)/(2)T_(0)`, the thermoelectric power isA. `1/2kT_(0)`B. `kT_(0)`C. `1/2kT_(0)^(2)`D. `1/2k(T_(0)-T_(r))^(2)` |
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Answer» a) Thermoelectric power, `S=(dE)/(dT) = d/(dT)[kT-T_(r).{T_(0) - 1/2(T+T_(r)}]` Specific latent heat of vaporisatioin `= (22.68 xx 10^(5)`J/kg= `X xx 10^(-3) xx 22.68 xx 10^(5)` ltrbgt `=Y xx 10^(-3) xx 3.36 xx 10^(5) + Y xx 10^(-3) xx 4200 xx 100)` `therefore` `X/Y = (7.56)/(22.68) = 1/3` `S=k(T-T_(r) xx (-1/2) + [T_(0) - 1/2(T_(0)/2 + T_(r))} xx k` When `T=T_(0)/2` `S= -k/2(T_(0)/2-T_(r)) + {T_(0)-1/2(T_(0)/2+T_(r))} xx k` `=(-kT_(0))/4 + (kT_(r))/2 + kT_(0)-(kT_(0))/4 - (kT_(r))/2 = 1/2 kT_(0)` |
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