The maximum number of sub-levels,orbitals and electrons in $N$ shell of an atom are respectively

An oxide of an element is a gas and dissolves in water to give an acidic solution. The element belongs to

$A$ coil of wire of radius $r$ has $600$ turns and a self-inductance of $108 \ mH$. The self-inductance of a coil with the same radius and $500$ turns is: (in $mH$)

In which type of crops is the mass selection method used?

What is the maximum value of the force $F$ such that the block shown in the arrangement does not move (in $N$)? (Given: $m = \sqrt{3} \ kg$,$\mu = \frac{1}{2\sqrt{3}}$,$\theta = 60^\circ$)

Which set of elements forms stable,covalently bonded hydrogen-bonded hydrides?