The Bhopal gas tragedy of $1984$ was caused by:

The metal ion present in vitamin $B_{12}$ is

The most active phagocytic white blood cells are:

$A$ conducting ring is placed around the core of an electromagnet as shown in the figure. When key $K$ is pressed,the ring

The primitive prokaryotes responsible for the production of biogas from the dung of ruminant animals include the:

Assertion: The ferromagnetic substance does not obey Curie's law.
Reason: At Curie point, a ferromagnetic substance starts behaving as a paramagnetic substance.