When a system goes from state A to state B, it is supplied with 400 J of heat and it does 100 J of work.
(a) For this transition, what is the system's change in internal energy?
(b) If the system moves from B to A, what is the change in internal energy?
(c) If in moving from A to B along a different path in which `W_(AB)^'=400J` of work is done on the system, how much heat does it absorb?

Options

A. 250 J
B. 300 J
C. 350 J
D. 150 J

Answer

B

Explanation

Given , heat , `Q_(AB)=400J` work done , `W_(AB)=100J` internal energy, `U_(AB)` = ?
From the first law of thermodynamics,
`DeltaU_(AB)=Q_(AB)-W_(AB)=(400-100)J=300J`