If 30J energy is trapped at product level, then how much energy will be available to peacock as food in the following chain?
Plant → Mice → Snake → Peacock

(B) 0.03J,
According to the ten percent law given by Lindeman (1942), only 10% of the total energy is transferred at each trophic level. From producers, 10% of total energy is transferred to the primary carnivores. Only 10% of the herbivores productivity is utilised for raising productivity of primary carnivores. The rest is consumed in ingestion, respiration carnivores. The rest is consumed in ingestion, respiration, maintenance of body heat and other activities. Higher carnivores similarly are able to retain only 10% of energy present in primary carnivores. Accordingly, if plant trapped 30 J of energy, mice will have 3 J, snake will have 0.3 J and hence, peacock will have 0.03 J of energy.