For spontaneous cooling of a hot metal rod (system) in air

Options

(a) ΔSsystem > 0,ΔSunivers < 0
(b) ΔSsystem > 0,ΔSunivers < 0
(c) ΔSsystem < 0,ΔSunivers > 0
(d) ΔSsystem < 0,ΔSunivers < 0

Correct Answer:

ΔSsystem < 0,ΔSunivers > 0

Explanation:

If heat flows from system at temperature T(system) to the surrounding at temperature T(surr) then ΔS(sys) 0.