The accelerated aging of a lake by biological enrichment of its water is known as:

Select the incorrect option regarding biological magnification (biomagnification).

According to the $..........$ norms,the implementation of $.......$ vehicles was enforced across the country from $1^{st}$ April $2017$.

Fly-ash is a/an :

What is the intensity of sound in normal conversation?

Catalytic converters:
$I.$ These are fitted into automobiles for reducing emission of poisonous gases like $NO_x$ and $CO$.
$II.$ They have expensive metals like platinum,palladium,and rhodium as catalysts.
$III.$ As the exhaust emission passes through the catalytic converter,nitric oxide splits into nitrogen and oxygen; carbon monoxide is oxidized to carbon dioxide,and unburnt hydrocarbons are burnt completely into $CO_2$ and $H_2O$.
$IV.$ Motor vehicles fitted with catalytic converters should use unleaded petrol because lead in the petrol inactivates the catalyst.
Which of the statements given above are correct about catalytic converters?