$(a)$ What percentage of energy available at the producer level is transferred at successive trophic level in a food chain?
$(b)$ What percentage of the solar energy is trapped and utilised by the plants?

(N/A) According to the $10 \%$ Law of energy transfer,only $10 \%$ of the energy available at one trophic level is transferred to the next higher trophic level.
$(b)$ Green plants (producers) capture approximately $1 \%$ of the solar energy falling on their leaves and convert it into food energy through the process of photosynthesis.