If 10 joules of energy is available at the producer level, then amount of energy present at the level of secondary consumers is
Only 10 % of energy is transferred from one trophic level to the next trophic level of a food chain (ten percent law, given by Linderman). In the present case, the energy available at the producer level is 10 J. Hence energy at the primary consumer level would be 1 H (10% of 10 J). Similarly, at the secondary consumer level, the energy present will be 0.1 J (100 % of 1 J).