Two plastic cups are stacked with one inside the other. A small spacer holds the cups apart. Hot water is then added to the inner cup and a lid is fitted on top, as illustrated. Which statement is correct?
- AThe bench is heated by convection from the bottom of the outer cup.
- BThe lid reduces the energy lost by convection.
- CThere is no thermal conduction through the sides of either cup.
- DThermal radiation is prevented by the small air gap.