29B is true..read it somewhere...
but Asish's says Answer is A,B,C only...
MULTI
Q. Specific heat of a substance can be
(a) finite
(b) infinite
(c) zero
(d) negative
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9 Answers
29
106ans given ABC
while i also thought ABCD
B: think of phase change.. there specific heat cap. is infinte
4During freezing process dQ<0 and dT=0 and C=dQ/dT= -infinity
So I think D shud also be correct
13(d) kaise ho sakta hai.....how can v raise the temp. of a body by extracting heat frm it...(other cond. remaining a const.) ?? Moreover, how can degrees of freedom be negative ?
13Smthing i found....
" The reasons why a system in stable thermodynamic equilibrium cannot have a negative specific heat if it is either extensive or in contact with a heat bath are reviewed. It is shown that large-scale attractive forces cause negative specific heats in a microcanonical ensemble and a giant phase transition in a canonical ensemble.
The question of whether all normal phase transitions may not be generated by negative-specific-heat elements at a microscopic level is investigated by considering a simple model of a chemical dissociation. The microscopic negative-specific-heat elements that cause the transition are isolated."
( http://adsabs.harvard.edu/abs/1977MNRAS.181..405L )
1Answer
A) Polytropic
B) C=dQ/ndT ... isothermal C→∞
C) C=dQ/ndT ... adiabatic C=0
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D) degrees of freedom cannot be negative (agreed with avik)