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Physics · PYQ NEET UG 2019(2)
हिन्दी\( 1 \text{ g} \) of water, of volume \( 1 \text{ cm}^3 \) at \( 100^{\circ}\text{C} \), is converted into steam at same temperature under normal atmospheric pressure \( (= 1 \times 10^5 \text{ Pa}) \). The volume of steam formed equals \( 1671 \text{ cm}^3 \). If the specific latent heat of vaporisation of water is \( 2256 \text{ J/g} \), the change in internal energy is,
Correct answer · Option 3
\( 2089 \text{ J} \)
Explanation
Using \( \Delta U = \Delta Q - P\Delta V \), where \( \Delta Q = mL = 2256 \text{ J} \) and \( P\Delta V = 10^5 \times (1671 - 1) \times 10^{-6} = 167 \text{ J} \). Thus \( \Delta U = 2256 - 167 = 2089 \text{ J} \).
