Q157 / 180 · COMEDK 2024 (Memory Based) · Physics
A thermally insulated rigid container contains an ideal gas heated by a filament of resistance $100 \Omega$ through a current of 1 A for 5 min , then change in internal energy is
- A0 kJ
- B10 kJ
- C20 kJ
- Correct answerD30 kJ
Solution
Volume of the ideal gas is constant, so $W=0$.
Using first law of thermodynamics,
$\begin{aligned}<br/>\Delta Q & =\Delta U \Rightarrow \Delta U=i^2 R t \\<br/>& =1^2 \times 100 \times 5 \times 60 \\<br/>& =30 \times 10^3=30 \mathrm{~kJ}<br/>\end{aligned}$
Using first law of thermodynamics,
$\begin{aligned}<br/>\Delta Q & =\Delta U \Rightarrow \Delta U=i^2 R t \\<br/>& =1^2 \times 100 \times 5 \times 60 \\<br/>& =30 \times 10^3=30 \mathrm{~kJ}<br/>\end{aligned}$
Hence, the correct answer is option: 'D'.