A system absorbs 10 kJ of heat and does 4 kJ of work. The internal energy of the system

Question

A system absorbs 10 kJ of heat and does 4 kJ of work. The internal energy of the system (A) Decreases by 6 kJ (B) Increases by 6 kJ (C) Decreases by 14 kJ (D) Increases by 14 kJ

Tardigrade Admin · Accepted Answer

As per I st law, Δ U=q+w q =+10 kJ (heat is absorbed by the system) w=-4 k J (work is done by the system) ∴ Δ U=q+w=10-4 k J=+6 kJ

Q. A system absorbs $10 k J$ of heat and does $4 k J$ of work. The internal energy of the system

Decreases by 6 kJ

Increases by 6 kJ

Decreases by 14 kJ

Increases by 14 kJ

As per $I^{s t}$ law,
$Δ U = q + w$
$q = + 10 k J$ (heat is absorbed by the system)
$w = - 4 k J$ (work is done by the system)
$∴ Δ U = q + w = 10 - 4 k J = + 6 k J$

Q. A system absorbs 10kJ of heat and does 4kJ of work. The internal energy of the system