JEE MAIN - Physics (2016 - 9th April Morning Slot - No. 16)
200 g water is heated from 40oC to 60oC. Ignoring the slight expansion of water, the change in its internal energy is close to (Given specific heat of water = 4184 J/kg/K) :
8.4 kJ
4.2 kJ
16.7 kJ
167.4 kJ
설명
According to the first law of thermodynamics,
Q = $$\Delta $$u + w
For isochoric process Q = $$\Delta $$U = ms$$\Delta $$t
$$\Delta $$T = (233 $$-$$ 213) = 20 k
$$ \therefore $$ $$\Delta $$u = 0.2 $$ \times $$ 4184 $$ \times $$ 20 = 16.7 kJ
Q = $$\Delta $$u + w
For isochoric process Q = $$\Delta $$U = ms$$\Delta $$t
$$\Delta $$T = (233 $$-$$ 213) = 20 k
$$ \therefore $$ $$\Delta $$u = 0.2 $$ \times $$ 4184 $$ \times $$ 20 = 16.7 kJ