Question

A forest ecosystem having a lot of green plants has some foxes, lions and rabbits in it.

(f) If the sun provides 1000 J of energy to the plants, then how much energy will be transferred to fox through the food chain

Answer 1

If $1000J$ of energy is provided by sun to plants, the plant will absorb only $1$ of this energy to make food. $1$ of $1000J$ $=10J$. Further, applying the ten percent rule,
The rabbits will receive $10$of $10J$ i.e. $1J$.
$10$ of $1J=0.1J$ will be passed on to the foxes,.