Thermodynamics Ques 48
48. The internal energy change in a system that has absorbed $2$ kcals of heat and done $500$ $J$ of work is:
[2009]
(a) $6400 $ $J$
(b) $5400 $ $J$
(c) $7900 $ $J$
(d) $8900 $ $J$
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Answer:
Correct Answer: 48.(c)
Solution:
- (c) According to first law of thermodynamics
$Q=\Delta U+W$
$\Delta U=Q-W$
$=2 \times 4.2 \times 1000-500=8400-500$
$=7900 $ $J$
BETA
