The percentage of energy transferred to the higher trophic level in a food chain is ....... (in $\%$)

Assertion $A$: The amount of free energy in a system gradually decreases.
Reason $R$: During any transformation of energy,some amount of energy is lost in the form of heat.
Which option is correct for Assertion $A$ and Reason $R$?

The driving force of any ecosystem is

Assertion: Ecosystems are not exempt from the second law of thermodynamics.
Reason: In a food chain,energy flow is bidirectional.

If $20 \ J$ of energy is trapped at the producer level,then how much energy will be available to the peacock as food in the following food chain (in $J$)?
Plant $\rightarrow$ Mice $\rightarrow$ Snake $\rightarrow$ Peacock

Identify the trophic levels $(1, 2, 3$ and $4)$ in the provided figure.