Question

Change in internal energy, when 4 KJ of work is done on the system and 1 KJ heat is given out by the system, is:

Options

• + 1 KJ

• – 5 KJ

• + 5 KJ

• + 3 KJ

Answer 1

+ 3 KJ

Explanation:

According to the first law of thermodynamics,

ΔE = Q + W

Here; W = + 4 KJ  .....(∴ work done on the system)

Q = – 1 KJ  .....(∴ Heat is given out by the system)

ΔE = + 3 KJ