Question

tea cool faster in plate then in cup​

Answer 1

this is because the surface area of tea increases in plate than in cup

Answer 2

Ciao,
this is due to increase in surface area .as plate has more surface area so more molecules of tea are in contact with air and evaporation of more energy carried molecules (hotness ) happens leaving low energy molecules.while in. cup less molecules are in vontact with enviroment .thus less evaporation.
( do stirring of tea with a spoon in the cup.you will see that it becomes cold faster )hope ot helps.stay blessed☺