In a food chain, if 10,000 joules of energy is available to the producer, how much energy will be available to the secondary consumer to transfer it to the tertiary consumer ?

According to the 10% law of energy transfer in a food chain, only 10% of the energy available at one trophic level is transferred to the next trophic level.

1. Producer level: $10,000\text{ J}$
2. Primary Consumer level: $10\% \text{ of } 10,000\text{ J} = 1,000\text{ J}$
3. Secondary Consumer level: $10\% \text{ of } 1,000\text{ J} = 100\text{ J}$

Therefore, the energy available at the secondary consumer level is $100\text{ J}$. Out of this, the energy that can be transferred to the tertiary consumer (which is 10% of the secondary consumer's energy) is $10\text{ J}$.