Which of the following pairs of orbitals possess two nodal planes?

$A$ straight line passing through the origin $O$ meets the parallel lines $4x + 2y = 9$ and $2x + y + 6 = 0$ at points $P$ and $Q$ respectively. In what ratio does the point $O$ divide the line segment $PQ$?

In $Bryophytes$,sexual reproduction occurs through which organs?

Which of the following is a characteristic test for the phenolic group?

In an astronomical telescope in normal adjustment,a straight black line of length $L$ is drawn on the objective lens. The eyepiece forms a real image of this line. The length of this image is $l$. The magnification of the telescope is

The eccentricity of the ellipse $x^2+4y^2+2x+16y+13=0$ is