1 g of a liquid is converted to vapour at Pa pressure. If 10% of the heat supplied is used for increasing the volume by 1600 cm during this phase change, then the increase in internal energy in the process will be:
- A.J
- B.4800 J
- C.4320 J
- D.432000 J
Show answer and solution
Correct option: C
Solution
The work done in expansion is W = P·ΔV = 3×10⁵ Pa × 1600×10⁻⁶ m³ = 480 J.
This 480 J represents 10% of the total heat supplied, so total heat Q = 480/0.10 = 4800 J.
The increase in internal energy ΔU = Q − W = 4800 − 480 = 4320 J.
This 480 J represents 10% of the total heat supplied, so total heat Q = 480/0.10 = 4800 J.
The increase in internal energy ΔU = Q − W = 4800 − 480 = 4320 J.
[JEE Main 2023 · 24 Jan · Shift 1 · Paper-1(B.E./B. Tech.)]