A Fixed mass of an ideal gas absorbs 1000 J of heat and expands under a constant pressure of 20 kPa from a volume of 25 x 10^-3 m3 to a volume of 50 x 10^-3 m3 . What is the change in internal energy of the gas?
Correct answer: D. +500 J
- A. +1000 J
- B. +5000 J
- C. 0J
- D. +500 J
Explanation
W = PΔVΔV = V2 - V1ΔV = 50 * 10-3 - 25 * 10-3 ΔV = 25 * 10-3 W = 20,000 * 25 * 10-3 W = 500 JCalculate the change in internal energy. ΔU = Q - W ΔU = 1000 J - 500 J ΔU = 500 J
Last updated
About First Law of Thermodynamics
The first law relates heat supplied, work done and the change in internal energy through energy conservation. Problems use sign conventions and apply the law to isothermal, adiabatic, isobaric and isochoric processes. Internal energy is a state function, while heat and work depend on the path followed.
Practise Thermodynamics
714 free Thermodynamics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
110 J of heat is added to a gaseous system, whose internal energy change is 40 J, then the amount of external work done is
1st law of thermodynamics is consequence of conservation of
A Carnot engine operates between reservoirs at 600 K and 300 K. Its maximum possible efficiency is
A carnot engine working between 200k and 400k has a work output of 600 J per cycle. How much heat energy is supplied to the engine from the source of each cycle.
A chemical system is sealed in a strong rigid container at room temp and then heated vigorously change in work done during the process is: