The product of the lengths of the perpendiculars drawn from the point $(-1, 5)$ to the pair of lines $2x^2 - xy - 3y^2 + 6x + y + 4 = 0$ is

Which of the following orders is correct for the heat of hydrogenation of these compounds?

$\lim _{x \rightarrow 0} x^2 \sin \left(\frac{\pi}{x}\right)$ is equal to

The energy of an electron in the $3^{rd}$ orbit of a hydrogenic atom is $-E$. The energy of an electron in the first orbit will be

If the maximum velocity with which an electron can be emitted from a photocell is $4 \times 10^8 \,cm/sec$,the stopping potential is ............ $V$ (mass of electron $= 9 \times 10^{-31} \,kg$).

Read the following statements carefully and select the correct statements.
$(1)$ The wheat variety $Atlas-66$ has high protein content.
$(2)$ $SCP$ is an alternative source of protein for human and animal nutrition.
$(3)$ Plants developed through micropropagation are genetically different from the parent plant.
$(4)$ Semi-dwarf rice varieties were developed from $IR-8$ and $Taichung Native-1$.